hosts/(pb*|cs*)/squid.conf: update to the version from squid 2.5.34

note that they are slightly differnt than the file in pb7

--- profitbricks-build7-amd64/etc/squid/squid.conf	2017-08-11 16:55:24.241686336 +0200
+++ profitbricks-build2-i386/etc/squid/squid.conf	2017-08-11 17:27:46.597522357 +0200
@@ -3444,7 +3444,7 @@

 # Uncomment and adjust the following to add a disk cache directory.
 #cache_dir ufs /var/spool/squid 100 16 256
-cache_dir ufs /var/spool/squid 16384 16 1024
+cache_dir ufs /var/spool/squid 4096 16 1024

 #  TAG: store_dir_select_algorithm
 #	How Squid selects which cache_dir to use when the response

Signed-off-by: Mattia Rizzolo <mattia@debian.org>

1 files changed, 3420 insertions, 1241 deletions

diff --git a/hosts/profitbricks-build11-amd64/etc/squid/squid.conf b/hosts/profitbricks-build11-amd64/etc/squid/squid.conf
index 34be0ec5..ad1cdc47 100644
--- a/hosts/profitbricks-build11-amd64/etc/squid/squid.conf
+++ b/hosts/profitbricks-build11-amd64/etc/squid/squid.conf
@@ -1,4 +1,4 @@
-#	WELCOME TO SQUID 3.1.20
+#	WELCOME TO SQUID 3.5.23
 #	----------------------------
 #	
 #	This is the documentation for the Squid configuration file.
@@ -32,6 +32,188 @@
 #  This arbitrary restriction is to prevent recursive include references
 #  from causing Squid entering an infinite loop whilst trying to load
 #  configuration files.
+#
+#  Values with byte units
+#
+#	Squid accepts size units on some size related directives. All
+#	such directives are documented with a default value displaying
+#	a unit.
+#
+#	Units accepted by Squid are:
+#		bytes - byte
+#		KB - Kilobyte (1024 bytes)
+#		MB - Megabyte
+#		GB - Gigabyte
+#
+#  Values with spaces, quotes, and other special characters
+#
+#	Squid supports directive parameters with spaces, quotes, and other
+#	special characters. Surround such parameters with "double quotes". Use
+#	the configuration_includes_quoted_values directive to enable or
+#	disable that support.
+#
+#	Squid supports reading configuration option parameters from external
+#	files using the syntax:
+#		parameters("/path/filename")
+#	For example:
+#		acl whitelist dstdomain parameters("/etc/squid/whitelist.txt")
+#
+#  Conditional configuration
+#
+#	If-statements can be used to make configuration directives
+#	depend on conditions:
+#
+#	    if <CONDITION>
+#	        ... regular configuration directives ...
+#	    [else
+#	        ... regular configuration directives ...]
+#	    endif
+#
+#	The else part is optional. The keywords "if", "else", and "endif"
+#	must be typed on their own lines, as if they were regular
+#	configuration directives.
+#
+#	NOTE: An else-if condition is not supported.
+#
+#	These individual conditions types are supported:
+#
+#	    true
+#		Always evaluates to true.
+#	    false
+#		Always evaluates to false.
+#	    <integer> = <integer>
+#	        Equality comparison of two integer numbers.
+#
+#
+#  SMP-Related Macros
+#
+#	The following SMP-related preprocessor macros can be used.
+#
+#	${process_name} expands to the current Squid process "name"
+#	(e.g., squid1, squid2, or cache1).
+#
+#	${process_number} expands to the current Squid process
+#	identifier, which is an integer number (e.g., 1, 2, 3) unique
+#	across all Squid processes of the current service instance.
+#
+#	${service_name} expands into the current Squid service instance
+#	name identifier which is provided by -n on the command line.
+#
+
+#  TAG: broken_vary_encoding
+#	This option is not yet supported by Squid-3.
+#Default:
+# none
+
+#  TAG: cache_vary
+#	This option is not yet supported by Squid-3.
+#Default:
+# none
+
+#  TAG: error_map
+#	This option is not yet supported by Squid-3.
+#Default:
+# none
+
+#  TAG: external_refresh_check
+#	This option is not yet supported by Squid-3.
+#Default:
+# none
+
+#  TAG: location_rewrite_program
+#	This option is not yet supported by Squid-3.
+#Default:
+# none
+
+#  TAG: refresh_stale_hit
+#	This option is not yet supported by Squid-3.
+#Default:
+# none
+
+#  TAG: hierarchy_stoplist
+#	Remove this line. Use always_direct or cache_peer_access ACLs instead if you need to prevent cache_peer use.
+#Default:
+# none
+
+#  TAG: log_access
+#	Remove this line. Use acls with access_log directives to control access logging
+#Default:
+# none
+
+#  TAG: log_icap
+#	Remove this line. Use acls with icap_log directives to control icap logging
+#Default:
+# none
+
+#  TAG: ignore_ims_on_miss
+#	Remove this line. The HTTP/1.1 feature is now configured by 'cache_miss_revalidate'.
+#Default:
+# none
+
+#  TAG: chunked_request_body_max_size
+#	Remove this line. Squid is now HTTP/1.1 compliant.
+#Default:
+# none
+
+#  TAG: dns_v4_fallback
+#	Remove this line. Squid performs a 'Happy Eyeballs' algorithm, the 'fallback' algorithm is no longer relevant.
+#Default:
+# none
+
+#  TAG: emulate_httpd_log
+#	Replace this with an access_log directive using the format 'common' or 'combined'.
+#Default:
+# none
+
+#  TAG: forward_log
+#	Use a regular access.log with ACL limiting it to MISS events.
+#Default:
+# none
+
+#  TAG: ftp_list_width
+#	Remove this line. Configure FTP page display using the CSS controls in errorpages.css instead.
+#Default:
+# none
+
+#  TAG: ignore_expect_100
+#	Remove this line. The HTTP/1.1 feature is now fully supported by default.
+#Default:
+# none
+
+#  TAG: log_fqdn
+#	Remove this option from your config. To log FQDN use %>A in the log format.
+#Default:
+# none
+
+#  TAG: log_ip_on_direct
+#	Remove this option from your config. To log server or peer names use %<A in the log format.
+#Default:
+# none
+
+#  TAG: maximum_single_addr_tries
+#	Replaced by connect_retries. The behaviour has changed, please read the documentation before altering.
+#Default:
+# none
+
+#  TAG: referer_log
+#	Replace this with an access_log directive using the format 'referrer'.
+#Default:
+# none
+
+#  TAG: update_headers
+#	Remove this line. The feature is supported by default in storage types where update is implemented.
+#Default:
+# none
+
+#  TAG: url_rewrite_concurrency
+#	Remove this line. Set the 'concurrency=' option of url_rewrite_children instead.
+#Default:
+# none
+
+#  TAG: useragent_log
+#	Replace this with an access_log directive using the format 'useragent'.
+#Default:
+# none
 
 #  TAG: dns_testnames
 #	Remove this line. DNS is no longer tested on startup.
@@ -43,6 +225,10 @@
 #Default:
 # none
 
+#  TAG: zero_buffers
+#Default:
+# none
+
 #  TAG: incoming_rate
 #Default:
 # none
@@ -73,6 +259,49 @@
 #Default:
 # none
 
+#  TAG: wais_relay_host
+#	Replace this line with 'cache_peer' configuration.
+#Default:
+# none
+
+#  TAG: wais_relay_port
+#	Replace this line with 'cache_peer' configuration.
+#Default:
+# none
+
+# OPTIONS FOR SMP
+# -----------------------------------------------------------------------------
+
+#  TAG: workers
+#	Number of main Squid processes or "workers" to fork and maintain.
+#	0: "no daemon" mode, like running "squid -N ..."
+#	1: "no SMP" mode, start one main Squid process daemon (default)
+#	N: start N main Squid process daemons (i.e., SMP mode)
+#
+#	In SMP mode, each worker does nearly all what a single Squid daemon
+#	does (e.g., listen on http_port and forward HTTP requests).
+#Default:
+# SMP support disabled.
+
+#  TAG: cpu_affinity_map
+#	Usage: cpu_affinity_map process_numbers=P1,P2,... cores=C1,C2,...
+#
+#	Sets 1:1 mapping between Squid processes and CPU cores. For example,
+#
+#	    cpu_affinity_map process_numbers=1,2,3,4 cores=1,3,5,7
+#
+#	affects processes 1 through 4 only and places them on the first
+#	four even cores, starting with core #1.
+#
+#	CPU cores are numbered starting from 1. Requires support for
+#	sched_getaffinity(2) and sched_setaffinity(2) system calls.
+#
+#	Multiple cpu_affinity_map options are merged.
+#
+#	See also: workers
+#Default:
+# Let operating system decide.
+
 # OPTIONS FOR AUTHENTICATION
 # -----------------------------------------------------------------------------
 
@@ -80,7 +309,7 @@
 #	This is used to define parameters for the various authentication
 #	schemes supported by Squid.
 #
-#	format: auth_param scheme parameter [setting]
+#		format: auth_param scheme parameter [setting]
 #
 #	The order in which authentication schemes are presented to the client is
 #	dependent on the order the scheme first appears in config file. IE
@@ -114,228 +343,104 @@
 #	Ports flagged 'transparent', 'intercept', or 'tproxy' have
 #	authentication disabled.
 #
-#	=== Parameters for the basic scheme follow. ===
+#	=== Parameters common to all schemes. ===
 #
 #	"program" cmdline
-#	Specify the command for the external authenticator.  Such a program
-#	reads a line containing "username password" and replies "OK" or
-#	"ERR" in an endless loop. "ERR" responses may optionally be followed
-#	by a error description available as %m in the returned error page.
-#	If you use an authenticator, make sure you have 1 acl of type
-#	proxy_auth.
-#
-#	By default, the basic authentication scheme is not used unless a
-#	program is specified.
-#
-#	If you want to use the traditional NCSA proxy authentication, set
-#	this line to something like
-#
-#	auth_param basic program /usr/lib/squid/ncsa_auth /usr/etc/passwd
-#
-#	"utf8" on|off
-#	HTTP uses iso-latin-1 as characterset, while some authentication
-#	backends such as LDAP expects UTF-8. If this is set to on Squid will
-#	translate the HTTP iso-latin-1 charset to UTF-8 before sending the
-#	username & password to the helper.
-#
-#	"children" numberofchildren
-#	The number of authenticator processes to spawn. If you start too few
-#	Squid will have to wait for them to process a backlog of credential
-#	verifications, slowing it down. When password verifications are
-#	done via a (slow) network you are likely to need lots of
-#	authenticator processes.
-#	auth_param basic children 5
-#
-#	"concurrency" concurrency
-#	The number of concurrent requests the helper can process.
-#	The default of 0 is used for helpers who only supports
-#	one request at a time. Setting this changes the protocol used to
-#	include a channel number first on the request/response line, allowing
-#	multiple requests to be sent to the same helper in parallell without
-#	wating for the response.
-#	Must not be set unless it's known the helper supports this.
-#	auth_param basic concurrency 0
-#
-#	"realm" realmstring
-#	Specifies the realm name which is to be reported to the
-#	client for the basic proxy authentication scheme (part of
-#	the text the user will see when prompted their username and
-#	password). There is no default.
-#	auth_param basic realm Squid proxy-caching web server
-#
-#	"credentialsttl" timetolive
-#	Specifies how long squid assumes an externally validated
-#	username:password pair is valid for - in other words how
-#	often the helper program is called for that user. Set this
-#	low to force revalidation with short lived passwords.  Note
-#	setting this high does not impact your susceptibility
-#	to replay attacks unless you are using an one-time password
-#	system (such as SecureID).  If you are using such a system,
-#	you will be vulnerable to replay attacks unless you also
-#	use the max_user_ip ACL in an http_access rule.
-#
-#	"casesensitive" on|off
-#	Specifies if usernames are case sensitive. Most user databases are
-#	case insensitive allowing the same username to be spelled using both
-#	lower and upper case letters, but some are case sensitive. This
-#	makes a big difference for user_max_ip ACL processing and similar.
-#	auth_param basic casesensitive off
-#
-#	=== Parameters for the digest scheme follow ===
+#		Specifies the command for the external authenticator.
 #
-#	"program" cmdline
-#	Specify the command for the external authenticator.  Such
-#	a program reads a line containing "username":"realm" and
-#	replies with the appropriate H(A1) value hex encoded or
-#	ERR if the user (or his H(A1) hash) does not exists.
-#	See rfc 2616 for the definition of H(A1).
-#	"ERR" responses may optionally be followed by a error description
-#	available as %m in the returned error page.
-#
-#	By default, the digest authentication scheme is not used unless a
-#	program is specified.
-#
-#	If you want to use a digest authenticator, set this line to
-#	something like
-#
-#	auth_param digest program /usr/lib/squid/digest_pw_auth /usr/etc/digpass
-#
-#	"utf8" on|off
-#	HTTP uses iso-latin-1 as characterset, while some authentication
-#	backends such as LDAP expects UTF-8. If this is set to on Squid will
-#	translate the HTTP iso-latin-1 charset to UTF-8 before sending the
-#	username & password to the helper.
-#
-#	"children" numberofchildren
-#	The number of authenticator processes to spawn (no default).
-#	If you start too few Squid will have to wait for them to
-#	process a backlog of H(A1) calculations, slowing it down.
-#	When the H(A1) calculations are done via a (slow) network
-#	you are likely to need lots of authenticator processes.
-#	auth_param digest children 5
-#
-#	"realm" realmstring
-#	Specifies the realm name which is to be reported to the
-#	client for the digest proxy authentication scheme (part of
-#	the text the user will see when prompted their username and
-#	password). There is no default.
-#	auth_param digest realm Squid proxy-caching web server
-#
-#	"nonce_garbage_interval" timeinterval
-#	Specifies the interval that nonces that have been issued
-#	to client_agent's are checked for validity.
-#
-#	"nonce_max_duration" timeinterval
-#	Specifies the maximum length of time a given nonce will be
-#	valid for.
-#
-#	"nonce_max_count" number
-#	Specifies the maximum number of times a given nonce can be
-#	used.
+#		By default, each authentication scheme is not used unless a
+#		program is specified.
 #
-#	"nonce_strictness" on|off
-#	Determines if squid requires strict increment-by-1 behavior
-#	for nonce counts, or just incrementing (off - for use when
-#	useragents generate nonce counts that occasionally miss 1
-#	(ie, 1,2,4,6)). Default off.
+#		See http://wiki.squid-cache.org/Features/AddonHelpers for
+#		more details on helper operations and creating your own.
 #
-#	"check_nonce_count" on|off
-#	This directive if set to off can disable the nonce count check
-#	completely to work around buggy digest qop implementations in
-#	certain mainstream browser versions. Default on to check the
-#	nonce count to protect from authentication replay attacks.
+#	"key_extras" format
+#		Specifies a string to be append to request line format for
+#		the authentication helper. "Quoted" format values may contain
+#		spaces and logformat %macros. In theory, any logformat %macro
+#		can be used. In practice, a %macro expands as a dash (-) if
+#		the helper request is sent before the required macro
+#		information is available to Squid.
 #
-#	"post_workaround" on|off
-#	This is a workaround to certain buggy browsers who sends
-#	an incorrect request digest in POST requests when reusing
-#	the same nonce as acquired earlier on a GET request.
+#		By default, Squid uses request formats provided in
+#		scheme-specific examples below (search for %credentials).
 #
-#	=== NTLM scheme options follow ===
+#		The expanded key_extras value is added to the Squid credentials
+#		cache and, hence, will affect authentication. It can be used to
+#		autenticate different users with identical user names (e.g.,
+#		when user authentication depends on http_port).
 #
-#	"program" cmdline
-#	Specify the command for the external NTLM authenticator.
-#	Such a program reads exchanged NTLMSSP packets with
-#	the browser via Squid until authentication is completed.
-#	If you use an NTLM authenticator, make sure you have 1 acl
-#	of type proxy_auth.  By default, the NTLM authenticator_program
-#	is not used.
+#		Avoid adding frequently changing information to key_extras. For
+#		example, if you add user source IP, and it changes frequently
+#		in your environment, then max_user_ip ACL is going to treat
+#		every user+IP combination as a unique "user", breaking the ACL
+#		and wasting a lot of memory on those user records. It will also
+#		force users to authenticate from scratch whenever their IP
+#		changes.
 #
-#	auth_param ntlm program /usr/lib/squid/ntlm_auth
+#	"realm" string
+#		Specifies the protection scope (aka realm name) which is to be
+#		reported to the client for the authentication scheme. It is
+#		commonly part of the text the user will see when prompted for
+#		their username and password.
 #
-#	"children" numberofchildren
-#	The number of authenticator processes to spawn (no default).
-#	If you start too few Squid will have to wait for them to
-#	process a backlog of credential verifications, slowing it
-#	down. When credential verifications are done via a (slow)
-#	network you are likely to need lots of authenticator
-#	processes.
+#		For Basic the default is "Squid proxy-caching web server".
+#		For Digest there is no default, this parameter is mandatory.
+#		For NTLM and Negotiate this parameter is ignored.
 #
-#	auth_param ntlm children 5
+#	"children" numberofchildren [startup=N] [idle=N] [concurrency=N]
 #
-#	"keep_alive" on|off
-#	Whether to keep the connection open after the initial response where
-#	Squid tells the browser which schemes are supported by the proxy.
-#	Some browsers are known to present many login popups or to corrupt
-#	POST/PUT requests transfer if the connection is not closed.
-#	The default is currently OFF to avoid this, but may change.
-#	
-#	auth_param ntlm keep_alive on
+#		The maximum number of authenticator processes to spawn. If
+#		you start too few Squid will have to wait for them to process
+#		a backlog of credential verifications, slowing it down. When
+#		password verifications are done via a (slow) network you are
+#		likely to need lots of authenticator processes.
 #
-#	=== Options for configuring the NEGOTIATE auth-scheme follow ===
+#		The startup= and idle= options permit some skew in the exact
+#		amount run. A minimum of startup=N will begin during startup
+#		and reconfigure. Squid will start more in groups of up to
+#		idle=N in an attempt to meet traffic needs and to keep idle=N
+#		free above those traffic needs up to the maximum.
 #
-#	"program" cmdline
-#	Specify the command for the external Negotiate authenticator.
-#	This protocol is used in Microsoft Active-Directory enabled setups with
-#	the Microsoft Internet Explorer or Mozilla Firefox browsers.
-#	Its main purpose is to exchange credentials with the Squid proxy
-#	using the Kerberos mechanisms.
-#	If you use a Negotiate authenticator, make sure you have at least
-#	one acl of type proxy_auth active. By default, the negotiate
-#	authenticator_program is not used.
-#	The only supported program for this role is the ntlm_auth
-#	program distributed as part of Samba, version 4 or later.
-#
-#	auth_param negotiate program /usr/lib/squid/ntlm_auth --helper-protocol=gss-spnego
-#
-#	"children" numberofchildren
-#	The number of authenticator processes to spawn (no default).
-#	If you start too few Squid will have to wait for them to
-#	process a backlog of credential verifications, slowing it
-#	down. When crendential verifications are done via a (slow)
-#	network you are likely to need lots of authenticator
-#	processes.
-#	auth_param negotiate children 5
-#
-#	"keep_alive" on|off
-#	Whether to keep the connection open after the initial response where
-#	Squid tells the browser which schemes are supported by the proxy.
-#	Some browsers are known to present many login popups or to corrupt
-#	POST/PUT requests transfer if the connection is not closed.
-#	The default is currently OFF to avoid this, but may change.
-#	
-#	auth_param negotiate keep_alive on
+#		The concurrency= option sets the number of concurrent requests
+#		the helper can process.  The default of 0 is used for helpers
+#		who only supports one request at a time. Setting this to a
+#		number greater than 0 changes the protocol used to include a
+#		channel ID field first on the request/response line, allowing
+#		multiple requests to be sent to the same helper in parallel
+#		without waiting for the response.
 #
+#		Concurrency must not be set unless it's known the helper
+#		supports the input format with channel-ID fields.
+#
+#		NOTE: NTLM and Negotiate schemes do not support concurrency
+#			in the Squid code module even though some helpers can.
 #
-#	Examples:
 #
-##Recommended minimum configuration per scheme:
+#
+#	=== Example Configuration ===
+#
+#	This configuration displays the recommended authentication scheme
+#	order from most to least secure with recommended minimum configuration
+#	settings for each scheme:
+#
 ##auth_param negotiate program <uncomment and complete this line to activate>
-##auth_param negotiate children 5
+##auth_param negotiate children 20 startup=0 idle=1
 ##auth_param negotiate keep_alive on
 ##
-##auth_param ntlm program <uncomment and complete this line to activate>
-##auth_param ntlm children 5
-##auth_param ntlm keep_alive on
-##
-##auth_param digest program <uncomment and complete this line>
-##auth_param digest children 5
+##auth_param digest program <uncomment and complete this line to activate>
+##auth_param digest children 20 startup=0 idle=1
 ##auth_param digest realm Squid proxy-caching web server
 ##auth_param digest nonce_garbage_interval 5 minutes
 ##auth_param digest nonce_max_duration 30 minutes
 ##auth_param digest nonce_max_count 50
 ##
+##auth_param ntlm program <uncomment and complete this line to activate>
+##auth_param ntlm children 20 startup=0 idle=1
+##auth_param ntlm keep_alive on
+##
 ##auth_param basic program <uncomment and complete this line>
-##auth_param basic children 5
+##auth_param basic children 5 startup=5 idle=1
 ##auth_param basic realm Squid proxy-caching web server
 ##auth_param basic credentialsttl 2 hours
 #Default:
@@ -343,7 +448,7 @@
 
 #  TAG: authenticate_cache_garbage_interval
 #	The time period between garbage collection across the username cache.
-#	This is a tradeoff between memory utilization (long intervals - say
+#	This is a trade-off between memory utilization (long intervals - say
 #	2 days) and CPU (short intervals - say 1 minute). Only change if you
 #	have good reason to.
 #Default:
@@ -362,11 +467,11 @@
 #	this directive controls how long Squid remembers the IP
 #	addresses associated with each user.  Use a small value
 #	(e.g., 60 seconds) if your users might change addresses
-#	quickly, as is the case with dialups.   You might be safe
+#	quickly, as is the case with dialup.   You might be safe
 #	using a larger value (e.g., 2 hours) in a corporate LAN
 #	environment with relatively static address assignments.
 #Default:
-# authenticate_ip_ttl 0 seconds
+# authenticate_ip_ttl 1 second
 
 # ACCESS CONTROLS
 # -----------------------------------------------------------------------------
@@ -381,31 +486,66 @@
 #
 #	  ttl=n		TTL in seconds for cached results (defaults to 3600
 #	  		for 1 hour)
+#
 #	  negative_ttl=n
 #	  		TTL for cached negative lookups (default same
 #	  		as ttl)
-#	  children=n	Number of acl helper processes spawn to service
+#
+#	  grace=n	Percentage remaining of TTL where a refresh of a
+#			cached entry should be initiated without needing to
+#			wait for a new reply. (default is for no grace period)
+#
+#	  cache=n	The maximum number of entries in the result cache. The
+#			default limit is 262144 entries.  Each cache entry usually
+#			consumes at least 256 bytes. Squid currently does not remove
+#			expired cache entries until the limit is reached, so a proxy
+#			will sooner or later reach the limit. The expanded FORMAT
+#			value is used as the cache key, so if the details in FORMAT
+#			are highly variable, a larger cache may be needed to produce
+#			reduction in helper load.
+#
+#	  children-max=n
+#			Maximum number of acl helper processes spawned to service
 #			external acl lookups of this type. (default 5)
+#
+#	  children-startup=n
+#			Minimum number of acl helper processes to spawn during
+#			startup and reconfigure to service external acl lookups
+#			of this type. (default 0)
+#
+#	  children-idle=n
+#			Number of acl helper processes to keep ahead of traffic
+#			loads. Squid will spawn this many at once whenever load
+#			rises above the capabilities of existing processes.
+#			Up to the value of children-max. (default 1)
+#
 #	  concurrency=n	concurrency level per process. Only used with helpers
 #			capable of processing more than one query at a time.
-#	  cache=n	result cache size, 0 is unbounded (default)
-#	  grace=n	Percentage remaining of TTL where a refresh of a
-#			cached entry should be initiated without needing to
-#			wait for a new reply. (default 0 for no grace period)
-#	  protocol=2.5	Compatibility mode for Squid-2.5 external acl helpers
+#
+#	  protocol=2.5	Compatibility mode for Squid-2.5 external acl helpers.
+#
 #	  ipv4 / ipv6	IP protocol used to communicate with this helper.
 #			The default is to auto-detect IPv6 and use it when available.
 #
+#
 #	FORMAT specifications
 #
 #	  %LOGIN	Authenticated user login name
-#	  %EXT_USER	Username from external acl
+#	  %un		A user name. Expands to the first available name
+#	  		from the following list of information sources:
+#			- authenticated user name, like %ul or %LOGIN
+#			- user name sent by an external ACL, like %EXT_USER
+#			- SSL client name, like %us in logformat
+#			- ident user name, like %ui in logformat
+#	  %EXT_USER	Username from previous external acl
+#	  %EXT_LOG	Log details from previous external acl
+#	  %EXT_TAG	Tag from previous external acl
 #	  %IDENT	Ident user name
 #	  %SRC		Client IP
 #	  %SRCPORT	Client source port
 #	  %URI		Requested URI
 #	  %DST		Requested host
-#	  %PROTO	Requested protocol
+#	  %PROTO	Requested URL scheme
 #	  %PORT		Requested port
 #	  %PATH		Requested URL path
 #	  %METHOD	Request method
@@ -415,7 +555,10 @@
 #	  %USER_CERT	SSL User certificate in PEM format
 #	  %USER_CERTCHAIN SSL User certificate chain in PEM format
 #	  %USER_CERT_xx	SSL User certificate subject attribute xx
-#	  %USER_CA_xx	SSL User certificate issuer attribute xx
+#	  %USER_CA_CERT_xx SSL User certificate issuer attribute xx
+#	  %ssl::>sni	SSL client SNI sent to Squid
+#	  %ssl::<cert_subject SSL server certificate DN
+#	  %ssl::<cert_issuer SSL server certificate issuer DN
 #
 #	  %>{Header}	HTTP request header "Header"
 #	  %>{Hdr:member}
@@ -433,43 +576,101 @@
 #	  		list separator. ; can be any non-alphanumeric
 #			character.
 #
+#	  %ACL		The name of the ACL being tested.
+#	  %DATA		The ACL arguments. If not used then any arguments
+#			is automatically added at the end of the line
+#			sent to the helper.
+#			NOTE: this will encode the arguments as one token,
+#			whereas the default will pass each separately.
+#
 #	  %%		The percent sign. Useful for helpers which need
 #			an unchanging input format.
 #
-#	In addition to the above, any string specified in the referencing
-#	acl will also be included in the helper request line, after the
-#	specified formats (see the "acl external" directive)
 #
-#	The helper receives lines per the above format specification,
-#	and returns lines starting with OK or ERR indicating the validity
-#	of the request and optionally followed by additional keywords with
-#	more details.
+#	General request syntax:
+#
+#	  [channel-ID] FORMAT-values [acl-values ...]
+#
+#
+#	FORMAT-values consists of transaction details expanded with
+#	whitespace separation per the config file FORMAT specification
+#	using the FORMAT macros listed above.
+#
+#	acl-values consists of any string specified in the referencing
+#	config 'acl ... external' line. see the "acl external" directive.
+#
+#	Request values sent to the helper are URL escaped to protect
+#	each value in requests against whitespaces.
+#
+#	If using protocol=2.5 then the request sent to the helper is not
+#	URL escaped to protect against whitespace.
+#
+#	NOTE: protocol=3.0 is deprecated as no longer necessary.
+#
+#	When using the concurrency= option the protocol is changed by
+#	introducing a query channel tag in front of the request/response.
+#	The query channel tag is a number between 0 and concurrency-1.
+#	This value must be echoed back unchanged to Squid as the first part
+#	of the response relating to its request.
+#
+#
+#	The helper receives lines expanded per the above format specification
+#	and for each input line returns 1 line starting with OK/ERR/BH result
+#	code and optionally followed by additional keywords with more details.
+#
 #
 #	General result syntax:
 #
-#	  OK/ERR keyword=value ...
+#	  [channel-ID] result keyword=value ...
+#
+#	Result consists of one of the codes:
+#
+#	  OK
+#		the ACL test produced a match.
+#
+#	  ERR
+#		the ACL test does not produce a match.
+#
+#	  BH
+#		An internal error occurred in the helper, preventing
+#		a result being identified.
+#
+#	The meaning of 'a match' is determined by your squid.conf
+#	access control configuration. See the Squid wiki for details.
 #
 #	Defined keywords:
 #
 #	  user=		The users name (login)
+#
 #	  password=	The users password (for login= cache_peer option)
-#	  message=	Message describing the reason. Available as %o
-#	  		in error pages
-#	  tag=		Apply a tag to a request (for both ERR and OK results)
-#	  		Only sets a tag, does not alter existing tags.
+#
+#	  message=	Message describing the reason for this response.
+#			Available as %o in error pages.
+#			Useful on (ERR and BH results).
+#
+#	  tag=		Apply a tag to a request. Only sets a tag once,
+#			does not alter existing tags.
+#
 #	  log=		String to be logged in access.log. Available as
-#	  		%ea in logformat specifications
+#	  		%ea in logformat specifications.
 #
-#	If protocol=3.0 (the default) then URL escaping is used to protect
-#	each value in both requests and responses.
+#  	  clt_conn_tag= Associates a TAG with the client TCP connection.
+#			Please see url_rewrite_program related documentation
+#			for this kv-pair.
 #
-#	If using protocol=2.5 then all values need to be enclosed in quotes
-#	if they may contain whitespace, or the whitespace escaped using \.
-#	And quotes or \ characters within the keyword value must be \ escaped.
+#	Any keywords may be sent on any response whether OK, ERR or BH.
 #
-#	When using the concurrency= option the protocol is changed by
-#	introducing a query channel tag infront of the request/response.
-#	The query channel tag is a number between 0 and concurrency-1.
+#	All response keyword values need to be a single token with URL
+#	escaping, or enclosed in double quotes (") and escaped using \ on
+#	any double quotes or \ characters within the value. The wrapping
+#	double quotes are removed before the value is interpreted by Squid.
+#	\r and \n are also replace by CR and LF.
+#
+#	Some example key values:
+#
+#		user=John%20Smith
+#		user="John Smith"
+#		user="J. \"Bob\" Smith"
 #Default:
 # none
 
@@ -485,9 +686,23 @@
 #
 #	When using "file", the file should contain one item per line.
 #
-#	By default, regular expressions are CASE-SENSITIVE.
-#	To make them case-insensitive, use the -i option. To return case-sensitive
-#	use the +i option between patterns, or make a new ACL line without -i.
+#	Some acl types supports options which changes their default behaviour.
+#	The available options are:
+#
+#	-i,+i	By default, regular expressions are CASE-SENSITIVE. To make them
+#		case-insensitive, use the -i option. To return case-sensitive
+#		use the +i option between patterns, or make a new ACL line
+#		without -i.	
+#
+#	-n	Disable lookups and address type conversions.  If lookup or
+#		conversion is required because the parameter type (IP or
+#		domain name) does not match the message address type (domain
+#		name or IP), then the ACL would immediately declare a mismatch
+#		without any warnings or lookups.
+#
+#	--	Used to stop processing all options, in the case the first acl
+#		value has '-' character as first character (for example the '-'
+#		is a valid domain name)
 #
 #	Some acl types require suspending the current request in order
 #	to access some external data source.
@@ -498,29 +713,31 @@
 #
 #	***** ACL TYPES AVAILABLE *****
 #
-#	acl aclname src ip-address/netmask ...	# clients IP address [fast]
-#	acl aclname src addr1-addr2/netmask ...	# range of addresses [fast]
-#	acl aclname dst ip-address/netmask ...	# URL host's IP address [slow]
-#	acl aclname myip ip-address/netmask ...	# local socket IP address [fast]
+#	acl aclname src ip-address/mask ...	# clients IP address [fast]
+#	acl aclname src addr1-addr2/mask ...	# range of addresses [fast]
+#	acl aclname dst [-n] ip-address/mask ...	# URL host's IP address [slow]
+#	acl aclname localip ip-address/mask ... # IP address the client connected to [fast]
 #
 #	acl aclname arp      mac-address ... (xx:xx:xx:xx:xx:xx notation)
-#	  # The arp ACL requires the special configure option --enable-arp-acl.
-#	  # Furthermore, the ARP ACL code is not portable to all operating systems.
-#	  # It works on Linux, Solaris, Windows, FreeBSD, and some
-#	  # other *BSD variants.
 #	  # [fast]
+#	  # The 'arp' ACL code is not portable to all operating systems.
+#	  # It works on Linux, Solaris, Windows, FreeBSD, and some other
+#	  # BSD variants.
 #	  #
-#	  # NOTE: Squid can only determine the MAC address for clients that are on
-#	  # the same subnet. If the client is on a different subnet,
-#	  # then Squid cannot find out its MAC address.
+#	  # NOTE: Squid can only determine the MAC/EUI address for IPv4
+#	  # clients that are on the same subnet. If the client is on a
+#	  # different subnet, then Squid cannot find out its address.
+#	  #
+#	  # NOTE 2: IPv6 protocol does not contain ARP. MAC/EUI is either
+#	  # encoded directly in the IPv6 address or not available.
 #
 #	acl aclname srcdomain   .foo.com ...
 #	  # reverse lookup, from client IP [slow]
-#	acl aclname dstdomain   .foo.com ...
+#	acl aclname dstdomain [-n] .foo.com ...
 #	  # Destination server from URL [fast]
 #	acl aclname srcdom_regex [-i] \.foo\.com ...
 #	  # regex matching client name [slow]
-#	acl aclname dstdom_regex [-i] \.foo\.com ...
+#	acl aclname dstdom_regex [-n] [-i] \.foo\.com ...
 #	  # regex matching server [fast]
 #	  #
 #	  # For dstdomain and dstdom_regex a reverse lookup is tried if a IP
@@ -557,13 +774,17 @@
 #
 #	acl aclname url_regex [-i] ^http:// ...
 #	  # regex matching on whole URL [fast]
+#	acl aclname urllogin [-i] [^a-zA-Z0-9] ...
+#	  # regex matching on URL login field
 #	acl aclname urlpath_regex [-i] \.gif$ ...
 #	  # regex matching on URL path [fast]
 #
 #	acl aclname port 80 70 21 0-1024...   # destination TCP port [fast]
 #	                                      # ranges are alloed
-#	acl aclname myport 3128 ...	          # local socket TCP port [fast]
-#	acl aclname myportname 3128 ...       # http(s)_port name [fast]
+#	acl aclname localport 3128 ...	      # TCP port the client connected to [fast]
+#	                                      # NP: for interception mode this is usually '80'
+#
+#	acl aclname myportname 3128 ...       # *_port name [fast]
 #
 #	acl aclname proto HTTP FTP ...        # request protocol [fast]
 # 
@@ -632,6 +853,11 @@
 #	  # clients may appear to come from multiple addresses if they are
 #	  # going through proxy farms, so a limit of 1 may cause user problems.
 #
+#	acl aclname random probability
+#	  # Pseudo-randomly match requests. Based on the probability given.
+#	  # Probability may be written as a decimal (0.333), fraction (1/3)
+#	  # or ratio of matches:non-matches (3:5).
+#
 #	acl aclname req_mime_type [-i] mime-type ...
 #	  # regex match against the mime type of the request generated
 #	  # by the client. Can be used to detect file upload or some
@@ -663,11 +889,11 @@
 #
 #	acl aclname user_cert attribute values...
 #	  # match against attributes in a user SSL certificate
-#	  # attribute is one of DN/C/O/CN/L/ST [fast]
+#	  # attribute is one of DN/C/O/CN/L/ST or a numerical OID [fast]
 #
 #	acl aclname ca_cert attribute values...
 #	  # match against attributes a users issuing CA SSL certificate
-#	  # attribute is one of DN/C/O/CN/L/ST [fast]
+#	  # attribute is one of DN/C/O/CN/L/ST or a numerical OID  [fast]
 #
 #	acl aclname ext_user username ...
 #	acl aclname ext_user_regex [-i] pattern ...
@@ -675,7 +901,59 @@
 #	  # use REQUIRED to accept any non-null user name.
 #
 #	acl aclname tag tagvalue ...
-#	  # string match on tag returned by external acl helper [slow]
+#	  # string match on tag returned by external acl helper [fast]
+#	  # DEPRECATED. Only the first tag will match with this ACL.
+#	  # Use the 'note' ACL instead for handling multiple tag values.
+#
+#	acl aclname hier_code codename ...
+#	  # string match against squid hierarchy code(s); [fast]
+#	  #  e.g., DIRECT, PARENT_HIT, NONE, etc.
+#	  #
+#	  # NOTE: This has no effect in http_access rules. It only has
+#	  # effect in rules that affect the reply data stream such as
+#	  # http_reply_access.
+#
+#	acl aclname note name [value ...]
+#	  # match transaction annotation [fast]
+#	  # Without values, matches any annotation with a given name.
+#	  # With value(s), matches any annotation with a given name that
+#	  # also has one of the given values.
+#	  # Names and values are compared using a string equality test.
+#	  # Annotation sources include note and adaptation_meta directives
+#	  # as well as helper and eCAP responses.
+#
+#	acl aclname adaptation_service service ...
+#	  # Matches the name of any icap_service, ecap_service,
+#	  # adaptation_service_set, or adaptation_service_chain that Squid
+#	  # has used (or attempted to use) for the master transaction.
+#	  # This ACL must be defined after the corresponding adaptation
+#	  # service is named in squid.conf. This ACL is usable with
+#	  # adaptation_meta because it starts matching immediately after
+#	  # the service has been selected for adaptation.
+#
+#	acl aclname any-of acl1 acl2 ...
+#	  # match any one of the acls [fast or slow]
+#	  # The first matching ACL stops further ACL evaluation.
+#	  #
+#	  # ACLs from multiple any-of lines with the same name are ORed.
+#	  # For example, A = (a1 or a2) or (a3 or a4) can be written as
+#	  #   acl A any-of a1 a2
+#	  #   acl A any-of a3 a4
+#	  #
+#	  # This group ACL is fast if all evaluated ACLs in the group are fast
+#	  # and slow otherwise.
+#
+#	acl aclname all-of acl1 acl2 ... 
+#	  # match all of the acls [fast or slow]
+#	  # The first mismatching ACL stops further ACL evaluation.
+#	  #
+#	  # ACLs from multiple all-of lines with the same name are ORed.
+#	  # For example, B = (b1 and b2) or (b3 and b4) can be written as
+#	  #   acl B all-of b1 b2
+#	  #   acl B all-of b3 b4
+#	  #
+#	  # This group ACL is fast if all evaluated ACLs in the group are fast
+#	  # and slow otherwise.
 #
 #	Examples:
 #		acl macaddress arp 09:00:2b:23:45:67
@@ -685,14 +963,11 @@
 #		acl javascript rep_mime_type -i ^application/x-javascript$
 #
 #Default:
-# acl all src all
+# ACLs all, manager, localhost, and to_localhost are predefined.
 #
 #
 # Recommended minimum configuration:
-# (now built-in)
-#acl manager proto cache_object
-#acl localhost src 127.0.0.1/32 ::1
-#acl to_localhost dst 127.0.0.0/8 0.0.0.0/32 ::1
+#
 
 # Example rule allowing access from your local networks.
 # Adapt to list your (internal) IP networks from where browsing
@@ -716,39 +991,83 @@ acl Safe_ports port 591		# filemaker
 acl Safe_ports port 777		# multiling http
 acl CONNECT method CONNECT
 
+#  TAG: proxy_protocol_access
+#	Determine which client proxies can be trusted to provide correct
+#	information regarding real client IP address using PROXY protocol.
+#
+#	Requests may pass through a chain of several other proxies
+#	before reaching us. The original source details may by sent in:
+#		* HTTP message Forwarded header, or
+#		* HTTP message X-Forwarded-For header, or
+#		* PROXY protocol connection header.
+#
+#	This directive is solely for validating new PROXY protocol
+#	connections received from a port flagged with require-proxy-header.
+#	It is checked only once after TCP connection setup.
+#
+#	A deny match results in TCP connection closure.
+#
+#	An allow match is required for Squid to permit the corresponding
+#	TCP connection, before Squid even looks for HTTP request headers.
+#	If there is an allow match, Squid starts using PROXY header information
+#	to determine the source address of the connection for all future ACL
+#	checks, logging, etc.
+#
+#	SECURITY CONSIDERATIONS:
+#
+#		Any host from which we accept client IP details can place
+#		incorrect information in the relevant header, and Squid
+#		will use the incorrect information as if it were the
+#		source address of the request.  This may enable remote
+#		hosts to bypass any access control restrictions that are
+#		based on the client's source addresses.
+#
+#	This clause only supports fast acl types.
+#	See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
+#Default:
+# all TCP connections to ports with require-proxy-header will be denied
+
 #  TAG: follow_x_forwarded_for
-#	Allowing or Denying the X-Forwarded-For header to be followed to
-#	find the original source of a request.
+#	Determine which client proxies can be trusted to provide correct
+#	information regarding real client IP address.
 #
 #	Requests may pass through a chain of several other proxies
-#	before reaching us.  The X-Forwarded-For header will contain a
-#	comma-separated list of the IP addresses in the chain, with the
-#	rightmost address being the most recent.
+#	before reaching us. The original source details may by sent in:
+#		* HTTP message Forwarded header, or
+#		* HTTP message X-Forwarded-For header, or
+#		* PROXY protocol connection header.
+#
+#	PROXY protocol connections are controlled by the proxy_protocol_access
+#	directive which is checked before this.
 #
 #	If a request reaches us from a source that is allowed by this
-#	configuration item, then we consult the X-Forwarded-For header
-#	to see where that host received the request from.  If the
-#	X-Forwarded-For header contains multiple addresses, we continue
-#	backtracking until we reach an address for which we are not allowed
-#	to follow the X-Forwarded-For header, or until we reach the first
-#	address in the list. For the purpose of ACL used in the
-#	follow_x_forwarded_for directive the src ACL type always matches
-#	the address we are testing and srcdomain matches its rDNS.
+#	directive, then we trust the information it provides regarding
+#	the IP of the client it received from (if any).
+#
+#	For the purpose of ACLs used in this directive the src ACL type always
+#	matches the address we are testing and srcdomain matches its rDNS.
+#
+#	On each HTTP request Squid checks for X-Forwarded-For header fields.
+#	If found the header values are iterated in reverse order and an allow
+#	match is required for Squid to continue on to the next value.
+#	The verification ends when a value receives a deny match, cannot be
+#	tested, or there are no more values to test.
+#	NOTE: Squid does not yet follow the Forwarded HTTP header.
 #
 #	The end result of this process is an IP address that we will
 #	refer to as the indirect client address.  This address may
 #	be treated as the client address for access control, ICAP, delay
 #	pools and logging, depending on the acl_uses_indirect_client,
-#	icap_uses_indirect_client, delay_pool_uses_indirect_client and
-#	log_uses_indirect_client options.
+#	icap_uses_indirect_client, delay_pool_uses_indirect_client, 
+#	log_uses_indirect_client and tproxy_uses_indirect_client options.
 #
 #	This clause only supports fast acl types.
 #	See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
 #
 #	SECURITY CONSIDERATIONS:
 #
-#		Any host for which we follow the X-Forwarded-For header
-#		can place incorrect information in the header, and Squid
+#		Any host from which we accept client IP details can place
+#		incorrect information in the relevant header, and Squid
 #		will use the incorrect information as if it were the
 #		source address of the request.  This may enable remote
 #		hosts to bypass any access control restrictions that are
@@ -761,7 +1080,7 @@ acl CONNECT method CONNECT
 #		follow_x_forwarded_for allow localhost
 #		follow_x_forwarded_for allow my_other_proxy
 #Default:
-# follow_x_forwarded_for deny all
+# X-Forwarded-For header will be ignored.
 
 #  TAG: acl_uses_indirect_client	on|off
 #	Controls whether the indirect client address
@@ -787,10 +1106,41 @@ acl CONNECT method CONNECT
 #Default:
 # log_uses_indirect_client on
 
+#  TAG: tproxy_uses_indirect_client	on|off
+#	Controls whether the indirect client address
+#	(see follow_x_forwarded_for) is used instead of the
+#	direct client address when spoofing the outgoing client.
+#
+#	This has no effect on requests arriving in non-tproxy
+#	mode ports.
+#
+#	SECURITY WARNING: Usage of this option is dangerous
+#	and should not be used trivially. Correct configuration
+#	of follow_x_forwarded_for with a limited set of trusted
+#	sources is required to prevent abuse of your proxy.
+#Default:
+# tproxy_uses_indirect_client off
+
+#  TAG: spoof_client_ip
+#	Control client IP address spoofing of TPROXY traffic based on
+#	defined access lists.
+#
+#	spoof_client_ip allow|deny [!]aclname ...
+#
+#	If there are no "spoof_client_ip" lines present, the default
+#	is to "allow" spoofing of any suitable request.
+#
+#	Note that the cache_peer "no-tproxy" option overrides this ACL.
+#
+#	This clause supports fast acl types.
+#	See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
+#Default:
+# Allow spoofing on all TPROXY traffic.
+
 #  TAG: http_access
 #	Allowing or Denying access based on defined access lists
 #
-#	Access to the HTTP port:
+#	To allow or deny a message received on an HTTP, HTTPS, or FTP port:
 #	http_access allow|deny [!]aclname ...
 #
 #	NOTE on default values:
@@ -809,22 +1159,22 @@ acl CONNECT method CONNECT
 #	See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
 #
 #Default:
-# http_access deny all
+# Deny, unless rules exist in squid.conf.
 #
 
 #
 # Recommended minimum Access Permission configuration:
 #
-# Only allow cachemgr access from localhost
-http_access allow manager localhost
-http_access deny manager
-
 # Deny requests to certain unsafe ports
 http_access deny !Safe_ports
 
 # Deny CONNECT to other than secure SSL ports
 http_access deny CONNECT !SSL_ports
 
+# Only allow cachemgr access from localhost
+http_access allow localhost manager
+http_access deny manager
+
 # We strongly recommend the following be uncommented to protect innocent
 # web applications running on the proxy server who think the only
 # one who can access services on "localhost" is a local user
@@ -852,7 +1202,7 @@ http_access deny all
 #
 #	If not set then only http_access is used.
 #Default:
-# none
+# Allow, unless rules exist in squid.conf.
 
 #  TAG: http_reply_access
 #	Allow replies to client requests. This is complementary to http_access.
@@ -860,7 +1210,7 @@ http_access deny all
 #	http_reply_access allow|deny [!] aclname ...
 #
 #	NOTE: if there are no access lines present, the default is to allow
-#	all replies
+#	all replies.
 #
 #	If none of the access lines cause a match the opposite of the
 #	last line will apply. Thus it is good practice to end the rules
@@ -869,7 +1219,7 @@ http_access deny all
 #	This clause supports both fast and slow acl types.
 #	See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
 #Default:
-# none
+# Allow, unless rules exist in squid.conf.
 
 #  TAG: icp_access
 #	Allowing or Denying access to the ICP port based on defined
@@ -877,7 +1227,9 @@ http_access deny all
 #
 #	icp_access  allow|deny [!]aclname ...
 #
-#	See http_access for details
+#	NOTE: The default if no icp_access lines are present is to
+#	deny all traffic. This default may cause problems with peers
+#	using ICP.
 #
 #	This clause only supports fast acl types.
 #	See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
@@ -886,7 +1238,7 @@ http_access deny all
 ##icp_access allow localnet
 ##icp_access deny all
 #Default:
-# icp_access deny all
+# Deny, unless rules exist in squid.conf.
 
 #  TAG: htcp_access
 #	Allowing or Denying access to the HTCP port based on defined
@@ -894,11 +1246,12 @@ http_access deny all
 #
 #	htcp_access  allow|deny [!]aclname ...
 #
-#	See http_access for details
+#	See also htcp_clr_access for details on access control for
+#	cache purge (CLR) HTCP messages.
 #
 #	NOTE: The default if no htcp_access lines are present is to
 #	deny all traffic. This default may cause problems with peers
-#	using the htcp or htcp-oldsquid options.
+#	using the htcp option.
 #
 #	This clause only supports fast acl types.
 #	See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
@@ -907,48 +1260,47 @@ http_access deny all
 ##htcp_access allow localnet
 ##htcp_access deny all
 #Default:
-# htcp_access deny all
+# Deny, unless rules exist in squid.conf.
 
 #  TAG: htcp_clr_access
 #	Allowing or Denying access to purge content using HTCP based
-#	on defined access lists
+#	on defined access lists.
+#	See htcp_access for details on general HTCP access control.
 #
 #	htcp_clr_access  allow|deny [!]aclname ...
 #
-#	See http_access for details
-#
 #	This clause only supports fast acl types.
 #	See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
 #
 ## Allow HTCP CLR requests from trusted peers
-#acl htcp_clr_peer src 172.16.1.2
+#acl htcp_clr_peer src 192.0.2.2 2001:DB8::2
 #htcp_clr_access allow htcp_clr_peer
+#htcp_clr_access deny all
 #Default:
-# htcp_clr_access deny all
+# Deny, unless rules exist in squid.conf.
 
 #  TAG: miss_access
-#	Determins whether network access is permitted when satisfying a request.
+#	Determines whether network access is permitted when satisfying a request.
 #
 #	For example;
 #	    to force your neighbors to use you as a sibling instead of
 #	    a parent.
 #
-#		acl localclients src 172.16.0.0/16
-#		miss_access allow localclients
+#		acl localclients src 192.0.2.0/24 2001:DB8::a:0/64
 #		miss_access deny  !localclients
+#		miss_access allow all
 #
 #	This means only your local clients are allowed to fetch relayed/MISS
 #	replies from the network and all other clients can only fetch cached
 #	objects (HITs).
 #
-#
 #	The default for this setting allows all clients who passed the
 #	http_access rules to relay via this proxy.
 #
 #	This clause only supports fast acl types.
 #	See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
 #Default:
-# miss_access allow all
+# Allow, unless rules exist in squid.conf.
 
 #  TAG: ident_lookup_access
 #	A list of ACL elements which, if matched, cause an ident
@@ -972,7 +1324,7 @@ http_access deny all
 #	This clause only supports fast acl types.
 #	See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
 #Default:
-# ident_lookup_access deny all
+# Unless rules exist in squid.conf, IDENT is not fetched.
 
 #  TAG: reply_body_max_size	size [acl acl...]
 #	This option specifies the maximum size of a reply body. It can be
@@ -1009,23 +1361,22 @@ http_access deny all
 #		reply_body_max_size 10 MB
 #
 #Default:
-# none
+# No limit is applied.
 
 # NETWORK OPTIONS
 # -----------------------------------------------------------------------------
 
 #  TAG: http_port
-#	Usage:	port [options]
-#		hostname:port [options]
-#		1.2.3.4:port [options]
+#	Usage:	port [mode] [options]
+#		hostname:port [mode] [options]
+#		1.2.3.4:port [mode] [options]
 #
 #	The socket addresses where Squid will listen for HTTP client
 #	requests.  You may specify multiple socket addresses.
 #	There are three forms: port alone, hostname with port, and
 #	IP address with port.  If you specify a hostname or IP
 #	address, Squid binds the socket to that specific
-#	address.  This replaces the old 'tcp_incoming_address'
-#	option.  Most likely, you do not need to bind to a specific
+#	address. Most likely, you do not need to bind to a specific
 #	address, so you can use the port number alone.
 #
 #	If you are running Squid in accelerator mode, you
@@ -1037,48 +1388,184 @@ http_access deny all
 #
 #	You may specify multiple socket addresses on multiple lines.
 #
-#	Options:
+#	Modes:
 #
-#	   intercept	Support for IP-Layer interception of
-#			outgoing requests without browser settings.
-#			NP: disables authentication and IPv6 on the port.
+#	   intercept	Support for IP-Layer NAT interception delivering
+#			traffic to this Squid port.
+#			NP: disables authentication on the port.
 #
-#	   tproxy	Support Linux TPROXY for spoofing outgoing
-#			connections using the client IP address.
-#			NP: disables authentication and maybe IPv6 on the port.
+#	   tproxy	Support Linux TPROXY (or BSD divert-to) with spoofing
+#			of outgoing connections using the client IP address.
+#			NP: disables authentication on the port.
 #
-#	   accel	Accelerator mode. Also needs at least one of
-#			vhost / vport / defaultsite.
+#	   accel	Accelerator / reverse proxy mode
+#
+#	   ssl-bump	For each CONNECT request allowed by ssl_bump ACLs,
+#			establish secure connection with the client and with
+#			the server, decrypt HTTPS messages as they pass through
+#			Squid, and treat them as unencrypted HTTP messages,
+#			becoming the man-in-the-middle.
+#
+#			The ssl_bump option is required to fully enable
+#			bumping of CONNECT requests.
+#
+#	Omitting the mode flag causes default forward proxy mode to be used.
 #
-#	   allow-direct	Allow direct forwarding in accelerator mode. Normally
-#			accelerated requests are denied direct forwarding as if
-#			never_direct was used.
+#
+#	Accelerator Mode Options:
 #
 #	   defaultsite=domainname
 #			What to use for the Host: header if it is not present
 #			in a request. Determines what site (not origin server)
 #			accelerators should consider the default.
-#			Implies accel.
 #
-#	   vhost	Accelerator mode using Host header for virtual domain support.
-#			Also uses the port as specified in Host: header unless
-#			overridden by the vport option. Implies accel.
+#	   no-vhost	Disable using HTTP/1.1 Host header for virtual domain support.
+#
+#	   protocol=	Protocol to reconstruct accelerated and intercepted
+#			requests with. Defaults to HTTP/1.1 for http_port and
+#			HTTPS/1.1 for https_port.
+#			When an unsupported value is configured Squid will
+#			produce a FATAL error.
+#			Values: HTTP or HTTP/1.1, HTTPS or HTTPS/1.1
 #
 #	   vport	Virtual host port support. Using the http_port number
-#			instead of the port passed on Host: headers. Implies accel.
+#			instead of the port passed on Host: headers.
 #
 #	   vport=NN	Virtual host port support. Using the specified port
 #			number instead of the port passed on Host: headers.
-#			Implies accel.
 #
-#	   protocol=	Protocol to reconstruct accelerated requests with.
-#			Defaults to http.
+#	   act-as-origin
+#			Act as if this Squid is the origin server.
+#			This currently means generate new Date: and Expires:
+#			headers on HIT instead of adding Age:.
 #
 #	   ignore-cc	Ignore request Cache-Control headers.
 #
-#	   		Warning: This option violates HTTP specifications if
+#			WARNING: This option violates HTTP specifications if
 #			used in non-accelerator setups.
 #
+#	   allow-direct	Allow direct forwarding in accelerator mode. Normally
+#			accelerated requests are denied direct forwarding as if
+#			never_direct was used.
+#
+#			WARNING: this option opens accelerator mode to security
+#			vulnerabilities usually only affecting in interception
+#			mode. Make sure to protect forwarding with suitable
+#			http_access rules when using this.
+#
+#
+#	SSL Bump Mode Options:
+#	    In addition to these options ssl-bump requires TLS/SSL options.
+#
+#	   generate-host-certificates[=<on|off>]
+#			Dynamically create SSL server certificates for the
+#			destination hosts of bumped CONNECT requests.When 
+#			enabled, the cert and key options are used to sign
+#			generated certificates. Otherwise generated
+#			certificate will be selfsigned.
+#			If there is a CA certificate lifetime of the generated 
+#			certificate equals lifetime of the CA certificate. If
+#			generated certificate is selfsigned lifetime is three 
+#			years.
+#			This option is disabled by default. See the ssl-bump
+#			option above for more information.
+#			
+#	   dynamic_cert_mem_cache_size=SIZE
+#			Approximate total RAM size spent on cached generated
+#			certificates. If set to zero, caching is disabled.
+#
+#	TLS / SSL Options:
+#
+#	   cert=	Path to SSL certificate (PEM format).
+#
+#	   key=		Path to SSL private key file (PEM format)
+#			if not specified, the certificate file is
+#			assumed to be a combined certificate and
+#			key file.
+#
+#	   version=	The version of SSL/TLS supported
+#			    1	automatic (default)
+#			    2	SSLv2 only
+#			    3	SSLv3 only
+#			    4	TLSv1.0 only
+#			    5	TLSv1.1 only
+#			    6	TLSv1.2 only
+#
+#	   cipher=	Colon separated list of supported ciphers.
+#			NOTE: some ciphers such as EDH ciphers depend on
+#			      additional settings. If those settings are
+#			      omitted the ciphers may be silently ignored
+#			      by the OpenSSL library.
+#
+#	   options=	Various SSL implementation options. The most important
+#			being:
+#			    NO_SSLv2    Disallow the use of SSLv2
+#			    NO_SSLv3    Disallow the use of SSLv3
+#			    NO_TLSv1    Disallow the use of TLSv1.0
+#			    NO_TLSv1_1  Disallow the use of TLSv1.1
+#			    NO_TLSv1_2  Disallow the use of TLSv1.2
+#			    SINGLE_DH_USE Always create a new key when using
+#				      temporary/ephemeral DH key exchanges
+#			    NO_TICKET Disables TLS tickets extension
+#
+#			    SINGLE_ECDH_USE
+#				      Enable ephemeral ECDH key exchange.
+#				      The adopted curve should be specified
+#				      using the tls-dh option.
+#
+#			    ALL       Enable various bug workarounds
+#				      suggested as "harmless" by OpenSSL
+#				      Be warned that this reduces SSL/TLS
+#				      strength to some attacks.
+#			See OpenSSL SSL_CTX_set_options documentation for a
+#			complete list of options.
+#
+#	   clientca=	File containing the list of CAs to use when
+#			requesting a client certificate.
+#
+#	   cafile=	File containing additional CA certificates to
+#			use when verifying client certificates. If unset
+#			clientca will be used.
+#
+#	   capath=	Directory containing additional CA certificates
+#			and CRL lists to use when verifying client certificates.
+#
+#	   crlfile=	File of additional CRL lists to use when verifying
+#			the client certificate, in addition to CRLs stored in
+#			the capath. Implies VERIFY_CRL flag below.
+#
+#	   tls-dh=[curve:]file
+#			File containing DH parameters for temporary/ephemeral DH key
+#			exchanges, optionally prefixed by a curve for ephemeral ECDH
+#			key exchanges.
+#			See OpenSSL documentation for details on how to create the
+#			DH parameter file. Supported curves for ECDH can be listed
+#			using the "openssl ecparam -list_curves" command.
+#			WARNING: EDH and EECDH ciphers will be silently disabled if
+#				 this option is not set.
+#
+#	   sslflags=	Various flags modifying the use of SSL:
+#			    DELAYED_AUTH
+#				Don't request client certificates
+#				immediately, but wait until acl processing
+#				requires a certificate (not yet implemented).
+#			    NO_DEFAULT_CA
+#				Don't use the default CA lists built in
+#				to OpenSSL.
+#			    NO_SESSION_REUSE
+#				Don't allow for session reuse. Each connection
+#				will result in a new SSL session.
+#			    VERIFY_CRL
+#				Verify CRL lists when accepting client
+#				certificates.
+#			    VERIFY_CRL_ALL
+#				Verify CRL lists for all certificates in the
+#				client certificate chain.
+#
+#	   sslcontext=	SSL session ID context identifier.
+#
+#	Other Options:
+#
 #	   connection-auth[=on|off]
 #	                use connection-auth=off to tell Squid to prevent 
 #	                forwarding Microsoft connection oriented authentication
@@ -1100,22 +1587,6 @@ http_access deny all
 #			sporadically hang or never complete requests set
 #			disable-pmtu-discovery option to 'transparent'.
 #
-#	   ssl-bump 	Intercept each CONNECT request matching ssl_bump ACL,
-#			establish secure connection with the client and with
-#			the server, decrypt HTTP messages as they pass through
-#			Squid, and treat them as unencrypted HTTP messages,
-#			becoming the man-in-the-middle.
-#
-#			When this option is enabled, additional options become
-#			available to specify SSL-related properties of the
-#			client-side connection: cert, key, version, cipher,
-#			options, clientca, cafile, capath, crlfile, dhparams,
-#			sslflags, and sslcontext. See the https_port directive
-#			for more information on these options.
-#
-#			The ssl_bump option is required to fully enable
-#			the SslBump feature.
-#
 #	   name=	Specifies a internal name for the port. Defaults to
 #			the port specification (port or addr:port)
 #
@@ -1125,6 +1596,11 @@ http_access deny all
 #			probing the connection, interval how often to probe, and
 #			timeout the time before giving up.
 #
+#	   require-proxy-header
+#			Require PROXY protocol version 1 or 2 connections.
+#			The proxy_protocol_access is required to whitelist
+#			downstream proxies which can be trusted.
+#
 #	If you run Squid on a dual-homed machine with an internal
 #	and an external interface we recommend you to specify the
 #	internal address:port in http_port. This way Squid will only be
@@ -1137,35 +1613,49 @@ http_port 3128
 
 #  TAG: https_port
 # Note: This option is only available if Squid is rebuilt with the
-#       --enable-ssl option
+#       --with-openssl
 #
-#	Usage:  [ip:]port cert=certificate.pem [key=key.pem] [options...]
+#	Usage:  [ip:]port cert=certificate.pem [key=key.pem] [mode] [options...]
 #
-#	The socket address where Squid will listen for HTTPS client
-#	requests.
+#	The socket address where Squid will listen for client requests made
+#	over TLS or SSL connections. Commonly referred to as HTTPS.
 #
-#	This is really only useful for situations where you are running
-#	squid in accelerator mode and you want to do the SSL work at the
-#	accelerator level.
+#	This is most useful for situations where you are running squid in
+#	accelerator mode and you want to do the SSL work at the accelerator level.
 #
 #	You may specify multiple socket addresses on multiple lines,
 #	each with their own SSL certificate and/or options.
 #
-#	Options:
+#	Modes:
+#
+#	   accel	Accelerator / reverse proxy mode
+#
+#	   intercept	Support for IP-Layer interception of
+#			outgoing requests without browser settings.
+#			NP: disables authentication and IPv6 on the port.
+#
+#	   tproxy	Support Linux TPROXY for spoofing outgoing
+#			connections using the client IP address.
+#			NP: disables authentication and maybe IPv6 on the port.
+#
+#	   ssl-bump	For each intercepted connection allowed by ssl_bump
+#			ACLs, establish a secure connection with the client and with
+#			the server, decrypt HTTPS messages as they pass through
+#			Squid, and treat them as unencrypted HTTP messages,
+#			becoming the man-in-the-middle.
 #
-#	   accel	Accelerator mode. Also needs at least one of
-#			defaultsite or vhost.
+#			An "ssl_bump server-first" match is required to
+#			fully enable bumping of intercepted SSL	connections.
 #
-#	   defaultsite=	The name of the https site presented on
-#	   		this port. Implies accel.
+#			Requires tproxy or intercept.
 #
-#	   vhost	Accelerator mode using Host header for virtual
-#			domain support. Requires a wildcard certificate
-#			or other certificate valid for more than one domain.
-#			Implies accel.
+#	Omitting the mode flag causes default forward proxy mode to be used.
 #
-#	   protocol=	Protocol to reconstruct accelerated requests with.
-#			Defaults to https.
+#
+#	See http_port for a list of generic options
+#
+#
+#	SSL Options:
 #
 #	   cert=	Path to SSL certificate (PEM format).
 #
@@ -1181,20 +1671,23 @@ http_port 3128
 #			    4	TLSv1 only
 #
 #	   cipher=	Colon separated list of supported ciphers.
-#			NOTE: some ciphers such as EDH ciphers depend on
-#			      additional settings. If those settings are
-#			      omitted the ciphers may be silently ignored
-#			      by the OpenSSL library.
 #
 #	   options=	Various SSL engine options. The most important
 #			being:
 #			    NO_SSLv2  Disallow the use of SSLv2
 #			    NO_SSLv3  Disallow the use of SSLv3
 #			    NO_TLSv1  Disallow the use of TLSv1
+#
 #			    SINGLE_DH_USE Always create a new key when using
 #				      temporary/ephemeral DH key exchanges
-#			See OpenSSL SSL_CTX_set_options documentation for a
-#			complete list of options.
+#
+#			    SINGLE_ECDH_USE
+#				      Enable ephemeral ECDH key exchange.
+#				      The adopted curve should be specified
+#				      using the tls-dh option.
+#
+#			See src/ssl_support.c or OpenSSL SSL_CTX_set_options
+#			documentation for a complete list of options.
 #
 #	   clientca=	File containing the list of CAs to use when
 #			requesting a client certificate.
@@ -1210,11 +1703,10 @@ http_port 3128
 #			the client certificate, in addition to CRLs stored in
 #			the capath. Implies VERIFY_CRL flag below.
 #
-#	   dhparams=	File containing DH parameters for temporary/ephemeral
-#			DH key exchanges. See OpenSSL documentation for details
-#			on how to create this file.
-#			WARNING: EDH ciphers will be silently disabled if this
-#				 option is not set.
+#	   tls-dh=[curve:]file
+#			File containing DH parameters for temporary/ephemeral DH key
+#			exchanges, optionally prefixed by a curve for ephemeral ECDH
+#			key exchanges.
 #
 #	   sslflags=	Various flags modifying the use of SSL:
 #			    DELAYED_AUTH
@@ -1238,38 +1730,89 @@ http_port 3128
 #
 #	   generate-host-certificates[=<on|off>]
 #			Dynamically create SSL server certificates for the
-#			destination hosts of bumped CONNECT requests.When 
+#			destination hosts of bumped SSL requests.When
 #			enabled, the cert and key options are used to sign
 #			generated certificates. Otherwise generated
 #			certificate will be selfsigned.
-#			If there is CA certificate life time of generated 
+#			If there is CA certificate life time of generated
 #			certificate equals lifetime of CA certificate. If
-#			generated certificate is selfsigned lifetime is three 
+#			generated certificate is selfsigned lifetime is three
 #			years.
-#			This option is enabled by default when SslBump is used.
-#			See the sslBump option above for more information.
-#			
+#			This option is disabled by default. See the ssl-bump
+#			option above for more information.
+#
 #	   dynamic_cert_mem_cache_size=SIZE
 #			Approximate total RAM size spent on cached generated
-#			certificates. If set to zero, caching is disabled. The
-#			default value is 4MB. An average XXX-bit certificate
-#			consumes about XXX bytes of RAM.
+#			certificates. If set to zero, caching is disabled.
 #
-#	   vport	Accelerator with IP based virtual host support.
+#	See http_port for a list of available options.
+#Default:
+# none
+
+#  TAG: ftp_port
+#	Enables Native FTP proxy by specifying the socket address where Squid
+#	listens for FTP client requests. See http_port directive for various
+#	ways to specify the listening address and mode.
 #
-#	   vport=NN	As above, but uses specified port number rather
-#			than the https_port number. Implies accel.
+#	Usage: ftp_port address [mode] [options]
 #
-#	   name=	Specifies a internal name for the port. Defaults to
-#			the port specification (port or addr:port)
+#	WARNING: This is a new, experimental, complex feature that has seen
+#	limited production exposure. Some Squid modules (e.g., caching) do not
+#	currently work with native FTP proxying, and many features have not
+#	even been tested for compatibility. Test well before deploying!
+#
+#	Native FTP proxying differs substantially from proxying HTTP requests
+#	with ftp:// URIs because Squid works as an FTP server and receives
+#	actual FTP commands (rather than HTTP requests with FTP URLs).
+#
+#	Native FTP commands accepted at ftp_port are internally converted or
+#	wrapped into HTTP-like messages. The same happens to Native FTP
+#	responses received from FTP origin servers. Those HTTP-like messages
+#	are shoveled through regular access control and adaptation layers
+#	between the FTP client and the FTP origin server. This allows Squid to
+#	examine, adapt, block, and log FTP exchanges. Squid reuses most HTTP
+#	mechanisms when shoveling wrapped FTP messages. For example,
+#	http_access and adaptation_access directives are used.
 #
+#	Modes:
+#
+#	   intercept	Same as http_port intercept. The FTP origin address is
+#			determined based on the intended destination of the
+#			intercepted connection.
+#
+#	   tproxy	Support Linux TPROXY for spoofing outgoing
+#			connections using the client IP address.
+#			NP: disables authentication and maybe IPv6 on the port.
+#
+#	By default (i.e., without an explicit mode option), Squid extracts the
+#	FTP origin address from the login@origin parameter of the FTP USER
+#	command. Many popular FTP clients support such native FTP proxying.
+#
+#	Options:
+#
+#	   name=token	Specifies an internal name for the port. Defaults to
+#			the port address. Usable with myportname ACL.
+#
+#	   ftp-track-dirs
+#			Enables tracking of FTP directories by injecting extra
+#			PWD commands and adjusting Request-URI (in wrapping
+#			HTTP requests) to reflect the current FTP server
+#			directory. Tracking is disabled by default.
+#
+#	   protocol=FTP	Protocol to reconstruct accelerated and intercepted
+#			requests with. Defaults to FTP. No other accepted
+#			values have been tested with. An unsupported value
+#			results in a FATAL error. Accepted values are FTP,
+#			HTTP (or HTTP/1.1), and HTTPS (or HTTPS/1.1).
+#
+#	Other http_port modes and options that are not specific to HTTP and
+#	HTTPS may also work.
 #Default:
 # none
 
 #  TAG: tcp_outgoing_tos
-#	Allows you to select a TOS/Diffserv value to mark outgoing
-#	connections with, based on the username or source address
-#	making the request.
+#	Allows you to select a TOS/Diffserv value for packets outgoing
+#	on the server side, based on an ACL.
 #
 #	tcp_outgoing_tos ds-field [!]aclname ...
 #
@@ -1286,41 +1829,116 @@ http_port 3128
 #	RFC2475, and RFC3260.
 #
 #	The TOS/DSCP byte must be exactly that - a octet value  0 - 255, or
-#	"default" to use whatever default your host has. Note that in
-#	practice often only multiples of 4 is usable as the two rightmost bits
-#	have been redefined for use by ECN (RFC 3168 section 23.1).
+#	"default" to use whatever default your host has.
+#	Note that only multiples of 4 are usable as the two rightmost bits have
+#	been redefined for use by ECN (RFC 3168 section 23.1).
+#	The squid parser will enforce this by masking away the ECN bits.
 #
 #	Processing proceeds in the order specified, and stops at first fully
 #	matching line.
 #
-#	Note: The use of this directive using client dependent ACLs is
-#	incompatible with the use of server side persistent connections. To
-#	ensure correct results it is best to set server_persistent_connections
-#	to off when using this directive in such configurations.
+#	Only fast ACLs are supported.
 #Default:
 # none
 
 #  TAG: clientside_tos
-#	Allows you to select a TOS/Diffserv value to mark client-side
-#	connections with, based on the username or source address
-#	making the request.
+#	Allows you to select a TOS/DSCP value for packets being transmitted
+#	on the client-side, based on an ACL.
+#
+#	clientside_tos ds-field [!]aclname ...
+#
+#	Example where normal_service_net uses the TOS value 0x00
+#	and good_service_net uses 0x20
+#
+#	acl normal_service_net src 10.0.0.0/24
+#	acl good_service_net src 10.0.1.0/24
+#	clientside_tos 0x00 normal_service_net
+#	clientside_tos 0x20 good_service_net
+#
+#	Note: This feature is incompatible with qos_flows. Any TOS values set here
+#	will be overwritten by TOS values in qos_flows.
+#
+#	The TOS/DSCP byte must be exactly that - a octet value  0 - 255, or
+#	"default" to use whatever default your host has.
+#	Note that only multiples of 4 are usable as the two rightmost bits have
+#	been redefined for use by ECN (RFC 3168 section 23.1).
+#	The squid parser will enforce this by masking away the ECN bits.
+#
+#Default:
+# none
+
+#  TAG: tcp_outgoing_mark
+# Note: This option is only available if Squid is rebuilt with the
+#       Packet MARK (Linux)
+#
+#	Allows you to apply a Netfilter mark value to outgoing packets
+#	on the server side, based on an ACL.
+#
+#	tcp_outgoing_mark mark-value [!]aclname ...
+#
+#	Example where normal_service_net uses the mark value 0x00
+#	and good_service_net uses 0x20
+#
+#	acl normal_service_net src 10.0.0.0/24
+#	acl good_service_net src 10.0.1.0/24
+#	tcp_outgoing_mark 0x00 normal_service_net
+#	tcp_outgoing_mark 0x20 good_service_net
+#
+#	Only fast ACLs are supported.
+#Default:
+# none
+
+#  TAG: clientside_mark
+# Note: This option is only available if Squid is rebuilt with the
+#       Packet MARK (Linux)
+#
+#	Allows you to apply a Netfilter mark value to packets being transmitted
+#	on the client-side, based on an ACL.
+#
+#	clientside_mark mark-value [!]aclname ...
+#
+#	Example where normal_service_net uses the mark value 0x00
+#	and good_service_net uses 0x20
+#
+#	acl normal_service_net src 10.0.0.0/24
+#	acl good_service_net src 10.0.1.0/24
+#	clientside_mark 0x00 normal_service_net
+#	clientside_mark 0x20 good_service_net
+#
+#	Note: This feature is incompatible with qos_flows. Any mark values set here
+#	will be overwritten by mark values in qos_flows.
 #Default:
 # none
 
 #  TAG: qos_flows
 #	Allows you to select a TOS/DSCP value to mark outgoing
-#	connections with, based on where the reply was sourced.
+#	connections to the client, based on where the reply was sourced.
+#	For platforms using netfilter, allows you to set a netfilter mark
+#	value instead of, or in addition to, a TOS value.
+#
+#	By default this functionality is disabled. To enable it with the default
+#	settings simply use "qos_flows mark" or "qos_flows tos". Default
+#	settings will result in the netfilter mark or TOS value being copied
+#	from the upstream connection to the client. Note that it is the connection
+#	CONNMARK value not the packet MARK value that is copied.
+#
+#	It is not currently possible to copy the mark or TOS value from the
+#	client to the upstream connection request.
 #
 #	TOS values really only have local significance - so you should
 #	know what you're specifying. For more information, see RFC2474,
 #	RFC2475, and RFC3260.
 #
-#	The TOS/DSCP byte must be exactly that - octet value 0x00-0xFF.
-#	Note that in practice often only values up to 0x3F are usable
-#	as the two highest bits have been redefined for use by ECN
-#	(RFC3168).
+#	The TOS/DSCP byte must be exactly that - a octet value  0 - 255.
+#	Note that only multiples of 4 are usable as the two rightmost bits have
+#	been redefined for use by ECN (RFC 3168 section 23.1).
+#	The squid parser will enforce this by masking away the ECN bits.
+#
+#	Mark values can be any unsigned 32-bit integer value.
+#
+#	This setting is configured by setting the following values:
 #
-#	This setting is configured by setting the source TOS values:
+#	tos|mark                Whether to set TOS or netfilter mark values
 #
 #	local-hit=0xFF		Value to mark local cache hits.
 #
@@ -1328,23 +1946,37 @@ http_port 3128
 #
 #	parent-hit=0xFF		Value to mark hits from parent peers.
 #
+#	miss=0xFF[/mask]	Value to mark cache misses. Takes precedence
+#				over the preserve-miss feature (see below), unless
+#				mask is specified, in which case only the bits
+#				specified in the mask are written.
 #
-#	NOTE: 'miss' preserve feature is only possible on Linux at this time.
-#
-#	For the following to work correctly, you will need to patch your
-#	linux kernel with the TOS preserving ZPH patch.
-#	The kernel patch can be downloaded from http://zph.bratcheda.org
+#	The TOS variant of the following features are only possible on Linux
+#	and require your kernel to be patched with the TOS preserving ZPH
+#	patch, available from http://zph.bratcheda.org
+#	No patch is needed to preserve the netfilter mark, which will work
+#	with all variants of netfilter.
 #
 #	disable-preserve-miss
-#		By default, the existing TOS value of the response coming
-#		from the remote server will be retained and masked with
-#		miss-mark. This option disables that feature.
+#		This option disables the preservation of the TOS or netfilter
+#		mark. By default, the existing TOS or netfilter mark value of
+#		the response coming from the remote server will be retained
+#		and masked with miss-mark.
+#		NOTE: in the case of a netfilter mark, the mark must be set on
+#		the connection (using the CONNMARK target) not on the packet
+#		(MARK target).
 #
 #	miss-mask=0xFF
-#		Allows you to mask certain bits in the TOS received from the
-#		remote server, before copying the value to the TOS sent
-#		towards clients.
-#		Default: 0xFF (TOS from server is not changed).
+#		Allows you to mask certain bits in the TOS or mark value
+#		received from the remote server, before copying the value to
+#		the TOS sent towards clients.
+#		Default for tos: 0xFF (TOS from server is not changed).
+#		Default for mark: 0xFFFFFFFF (mark from server is not changed).
+#
+#	All of these features require the --enable-zph-qos compilation flag
+#	(enabled by default). Netfilter marking also requires the
+#	libnetfilter_conntrack libraries (--with-netfilter-conntrack) and
+#	libcap 2.09+ (--with-libcap).
 #
 #Default:
 # none
@@ -1356,72 +1988,133 @@ http_port 3128
 #
 #	tcp_outgoing_address ipaddr [[!]aclname] ...
 #
-#	Example where requests from 10.0.0.0/24 will be forwarded
-#	with source address 10.1.0.1, 10.0.2.0/24 forwarded with
-#	source address 10.1.0.2 and the rest will be forwarded with
-#	source address 10.1.0.3.
-#
-#	acl normal_service_net src 10.0.0.0/24
-#	acl good_service_net src 10.0.2.0/24
-#	tcp_outgoing_address 10.1.0.1 normal_service_net
-#	tcp_outgoing_address 10.1.0.2 good_service_net
-#	tcp_outgoing_address 10.1.0.3
-#
-#	Processing proceeds in the order specified, and stops at first fully
-#	matching line.
-#
-#	Note: The use of this directive using client dependent ACLs is
-#	incompatible with the use of server side persistent connections. To
-#	ensure correct results it is best to set server_persistent_connections
-#	to off when using this directive in such configurations.
-#
+#	For example;
+#		Forwarding clients with dedicated IPs for certain subnets.
 #
-#        IPv6 Magic:
+#	  acl normal_service_net src 10.0.0.0/24
+#	  acl good_service_net src 10.0.2.0/24
 #
-#	Squid is built with a capability of bridging the IPv4 and IPv6 
-#	internets.
-#	tcp_outgoing_address as exampled above breaks this bridging by forcing
-#	all outbound traffic through a certain IPv4 which may be on the wrong
-#	side of the IPv4/IPv6 boundary.
+#	  tcp_outgoing_address 2001:db8::c001 good_service_net
+#	  tcp_outgoing_address 10.1.0.2 good_service_net
 #
-#	To operate with tcp_outgoing_address and keep the bridging benefits
-#	an additional ACL needs to be used which ensures the IPv6-bound traffic
-#	is never forced or permitted out the IPv4 interface.
+#	  tcp_outgoing_address 2001:db8::beef normal_service_net
+#	  tcp_outgoing_address 10.1.0.1 normal_service_net
 #
-#	# IPv6 destination test along with a dummy access control to perform the required DNS
-#	# This MUST be place before any ALLOW rules.
-#	acl to_ipv6 dst ipv6
-#	http_access deny ipv6 !all
+#	  tcp_outgoing_address 2001:db8::1
+#	  tcp_outgoing_address 10.1.0.3
 #
-#	tcp_outgoing_address 2001:db8::c001 good_service_net to_ipv6
-#	tcp_outgoing_address 10.1.0.2 good_service_net !to_ipv6
+#	Processing proceeds in the order specified, and stops at first fully
+#	matching line.
 #
-#	tcp_outgoing_address 2001:db8::beef normal_service_net to_ipv6
-#	tcp_outgoing_address 10.1.0.1 normal_service_net !to_ipv6
+#	Squid will add an implicit IP version test to each line.
+#	Requests going to IPv4 websites will use the outgoing 10.1.0.* addresses.
+#	Requests going to IPv6 websites will use the outgoing 2001:db8:* addresses.
 #
-#	tcp_outgoing_address 2001:db8::1 to_ipv6
-#	tcp_outgoing_address 10.1.0.3 !to_ipv6
 #
-#	WARNING:
-#	  'dst ipv6' bases its selection assuming DIRECT access.
-#	  If peers are used the peername ACL are needed to select outgoing
-#	  address which can link to the peer.
+#	NOTE: The use of this directive using client dependent ACLs is
+#	incompatible with the use of server side persistent connections. To
+#	ensure correct results it is best to set server_persistent_connections
+#	to off when using this directive in such configurations.
 #
-#	  'dst ipv6' is a slow ACL. It will only work here if 'dst' is used
-#	  previously in the http_access rules to locate the destination IP.
-#	  Some more magic may be needed for that:
-#	    http_access allow to_ipv6 !all
-#	  (meaning, allow if to IPv6 but not from anywhere ;)
+#	NOTE: The use of this directive to set a local IP on outgoing TCP links
+#	is incompatible with using TPROXY to set client IP out outbound TCP links.
+#	When needing to contact peers use the no-tproxy cache_peer option and the
+#	client_dst_passthru directive re-enable normal forwarding such as this.
 #
 #Default:
-# none
+# Address selection is performed by the operating system.
+
+#  TAG: host_verify_strict
+#	Regardless of this option setting, when dealing with intercepted
+#	traffic, Squid always verifies that the destination IP address matches
+#	the Host header domain or IP (called 'authority form URL').
+#	
+#	This enforcement is performed to satisfy a MUST-level requirement in
+#	RFC 2616 section 14.23: "The Host field value MUST represent the naming
+#	authority of the origin server or gateway given by the original URL".
+#	
+#	When set to ON:
+#		Squid always responds with an HTTP 409 (Conflict) error
+#		page and logs a security warning if there is no match.
+#	
+#		Squid verifies that the destination IP address matches
+#		the Host header for forward-proxy and reverse-proxy traffic
+#		as well. For those traffic types, Squid also enables the
+#		following checks, comparing the corresponding Host header
+#		and Request-URI components:
+#	
+#		 * The host names (domain or IP) must be identical,
+#		   but valueless or missing Host header disables all checks.
+#		   For the two host names to match, both must be either IP
+#		   or FQDN.
+#	
+#		 * Port numbers must be identical, but if a port is missing
+#		   the scheme-default port is assumed.
+#	
+#	
+#	When set to OFF (the default):
+#		Squid allows suspicious requests to continue but logs a
+#		security warning and blocks caching of the response.
+#	
+#		 * Forward-proxy traffic is not checked at all.
+#	
+#		 * Reverse-proxy traffic is not checked at all.
+#	
+#		 * Intercepted traffic which passes verification is handled
+#		   according to client_dst_passthru.
+#	
+#		 * Intercepted requests which fail verification are sent
+#		   to the client original destination instead of DIRECT.
+#		   This overrides 'client_dst_passthru off'.
+#	
+#		For now suspicious intercepted CONNECT requests are always
+#		responded to with an HTTP 409 (Conflict) error page.
+#	
+#	
+#	SECURITY NOTE:
+#	
+#	As described in CVE-2009-0801 when the Host: header alone is used
+#	to determine the destination of a request it becomes trivial for
+#	malicious scripts on remote websites to bypass browser same-origin
+#	security policy and sandboxing protections.
+#	
+#	The cause of this is that such applets are allowed to perform their
+#	own HTTP stack, in which case the same-origin policy of the browser
+#	sandbox only verifies that the applet tries to contact the same IP
+#	as from where it was loaded at the IP level. The Host: header may
+#	be different from the connected IP and approved origin.
+#	
+#Default:
+# host_verify_strict off
+
+#  TAG: client_dst_passthru
+#	With NAT or TPROXY intercepted traffic Squid may pass the request
+#	directly to the original client destination IP or seek a faster
+#	source using the HTTP Host header.
+#	
+#	Using Host to locate alternative servers can provide faster
+#	connectivity with a range of failure recovery options.
+#	But can also lead to connectivity trouble when the client and
+#	server are attempting stateful interactions unaware of the proxy.
+#	
+#	This option (on by default) prevents alternative DNS entries being
+#	located to send intercepted traffic DIRECT to an origin server.
+#	The clients original destination IP and port will be used instead.
+#	
+#	Regardless of this option setting, when dealing with intercepted
+#	traffic Squid will verify the Host: header and any traffic which
+#	fails Host verification will be treated as if this option were ON.
+#	
+#	see host_verify_strict for details on the verification process.
+#Default:
+# client_dst_passthru on
 
 # SSL OPTIONS
 # -----------------------------------------------------------------------------
 
 #  TAG: ssl_unclean_shutdown
 # Note: This option is only available if Squid is rebuilt with the
-#       --enable-ssl option
+#       --with-openssl
 #
 #	Some browsers (especially MSIE) bugs out on SSL shutdown
 #	messages.
@@ -1430,7 +2123,7 @@ http_port 3128
 
 #  TAG: ssl_engine
 # Note: This option is only available if Squid is rebuilt with the
-#       --enable-ssl option
+#       --with-openssl
 #
 #	The OpenSSL engine to use. You will need to set this if you
 #	would like to use hardware SSL acceleration for example.
@@ -1439,7 +2132,7 @@ http_port 3128
 
 #  TAG: sslproxy_client_certificate
 # Note: This option is only available if Squid is rebuilt with the
-#       --enable-ssl option
+#       --with-openssl
 #
 #	Client SSL Certificate to use when proxying https:// URLs
 #Default:
@@ -1447,7 +2140,7 @@ http_port 3128
 
 #  TAG: sslproxy_client_key
 # Note: This option is only available if Squid is rebuilt with the
-#       --enable-ssl option
+#       --with-openssl
 #
 #	Client SSL Key to use when proxying https:// URLs
 #Default:
@@ -1455,36 +2148,60 @@ http_port 3128
 
 #  TAG: sslproxy_version
 # Note: This option is only available if Squid is rebuilt with the
-#       --enable-ssl option
+#       --with-openssl
 #
 #	SSL version level to use when proxying https:// URLs
+#
+#	The versions of SSL/TLS supported:
+#
+#	    1	automatic (default)
+#	    2	SSLv2 only
+#	    3	SSLv3 only
+#	    4	TLSv1.0 only
+#	    5	TLSv1.1 only
+#	    6	TLSv1.2 only
 #Default:
-# sslproxy_version 1
+# automatic SSL/TLS version negotiation
 
 #  TAG: sslproxy_options
 # Note: This option is only available if Squid is rebuilt with the
-#       --enable-ssl option
+#       --with-openssl
 #
-#	SSL engine options to use when proxying https:// URLs
+#	Colon (:) or comma (,) separated list of SSL implementation options
+#	to use when proxying https:// URLs
 #	
 #	The most important being:
 #
-#		NO_SSLv2  Disallow the use of SSLv2
-#		NO_SSLv3  Disallow the use of SSLv3
-#		NO_TLSv1  Disallow the use of TLSv1
-#		SINGLE_DH_USE
-#			Always create a new key when using
-#			temporary/ephemeral DH key exchanges
+#	    NO_SSLv2    Disallow the use of SSLv2
+#	    NO_SSLv3    Disallow the use of SSLv3
+#	    NO_TLSv1    Disallow the use of TLSv1.0
+#	    NO_TLSv1_1  Disallow the use of TLSv1.1
+#	    NO_TLSv1_2  Disallow the use of TLSv1.2
+#
+#	    SINGLE_DH_USE
+#		      Always create a new key when using temporary/ephemeral
+#		      DH key exchanges
+#
+#	    NO_TICKET
+#		      Disable use of RFC5077 session tickets. Some servers
+#		      may have problems understanding the TLS extension due
+#		      to ambiguous specification in RFC4507.
+#
+#	    ALL       Enable various bug workarounds suggested as "harmless"
+#		      by OpenSSL. Be warned that this may reduce SSL/TLS
+#		      strength to some attacks.
 #	
-#	These options vary depending on your SSL engine.
 #	See the OpenSSL SSL_CTX_set_options documentation for a
 #	complete list of possible options.
+#	
+#	WARNING: This directive takes a single token. If a space is used
+#		 the value(s) after that space are SILENTLY IGNORED.
 #Default:
 # none
 
 #  TAG: sslproxy_cipher
 # Note: This option is only available if Squid is rebuilt with the
-#       --enable-ssl option
+#       --with-openssl
 #
 #	SSL cipher list to use when proxying https:// URLs
 #
@@ -1494,7 +2211,7 @@ http_port 3128
 
 #  TAG: sslproxy_cafile
 # Note: This option is only available if Squid is rebuilt with the
-#       --enable-ssl option
+#       --with-openssl
 #
 #	file containing CA certificates to use when verifying server
 #	certificates while proxying https:// URLs
@@ -1503,45 +2220,151 @@ http_port 3128
 
 #  TAG: sslproxy_capath
 # Note: This option is only available if Squid is rebuilt with the
-#       --enable-ssl option
+#       --with-openssl
 #
 #	directory containing CA certificates to use when verifying
 #	server certificates while proxying https:// URLs
 #Default:
 # none
 
-#  TAG: ssl_bump
+#  TAG: sslproxy_session_ttl
+# Note: This option is only available if Squid is rebuilt with the
+#       --with-openssl
+#
+#	Sets the timeout value for SSL sessions
+#Default:
+# sslproxy_session_ttl 300
+
+#  TAG: sslproxy_session_cache_size
+# Note: This option is only available if Squid is rebuilt with the
+#       --with-openssl
+#
+#        Sets the cache size to use for ssl session
+#Default:
+# sslproxy_session_cache_size 2 MB
+
+#  TAG: sslproxy_foreign_intermediate_certs
+# Note: This option is only available if Squid is rebuilt with the
+#       --with-openssl
+#
+#	Many origin servers fail to send their full server certificate
+#	chain for verification, assuming the client already has or can
+#	easily locate any missing intermediate certificates.
+#
+#	Squid uses the certificates from the specified file to fill in
+#	these missing chains when trying to validate origin server
+#	certificate chains.
+#
+#	The file is expected to contain zero or more PEM-encoded
+#	intermediate certificates. These certificates are not treated
+#	as trusted root certificates, and any self-signed certificate in
+#	this file will be ignored.
+#Default:
+# none
+
+#  TAG: sslproxy_cert_sign_hash
 # Note: This option is only available if Squid is rebuilt with the
-#       --enable-ssl option
+#       --with-openssl
 #
-#	This ACL controls which CONNECT requests to an http_port
-#	marked with an sslBump flag are actually "bumped". Please 
-#	see the sslBump flag of an http_port option for more details
-#	about decoding proxied SSL connections.
+#	Sets the hashing algorithm to use when signing generated certificates.
+#	Valid algorithm names depend on the OpenSSL library used. The following
+#	names are usually available: sha1, sha256, sha512, and md5. Please see
+#	your OpenSSL library manual for the available hashes. By default, Squids
+#	that support this option use sha256 hashes.
 #
-#	By default, no requests are bumped.
+#	Squid does not forcefully purge cached certificates that were generated
+#	with an algorithm other than the currently configured one. They remain
+#	in the cache, subject to the regular cache eviction policy, and become
+#	useful if the algorithm changes again.
+#Default:
+# none
+
+#  TAG: ssl_bump
+# Note: This option is only available if Squid is rebuilt with the
+#       --with-openssl
+#
+#	This option is consulted when a CONNECT request is received on
+#	an http_port (or a new connection is intercepted at an
+#	https_port), provided that port was configured with an ssl-bump
+#	flag. The subsequent data on the connection is either treated as
+#	HTTPS and decrypted OR tunneled at TCP level without decryption,
+#	depending on the first matching bumping "action".
+#
+#	ssl_bump <action> [!]acl ...
+#
+#	The following bumping actions are currently supported:
+#
+#	    splice
+#		Become a TCP tunnel without decrypting proxied traffic.
+#		This is the default action.
+#
+#	    bump
+#		Establish a secure connection with the server and, using a
+#		mimicked server certificate, with the client.
+#
+#	    peek
+#		Receive client (step SslBump1) or server (step SslBump2)
+#		certificate while preserving the possibility of splicing the
+#		connection. Peeking at the server certificate (during step 2)
+#		usually precludes bumping of the connection at step 3.
+#
+#	    stare
+#		Receive client (step SslBump1) or server (step SslBump2)
+#		certificate while preserving the possibility of bumping the
+#		connection. Staring at the server certificate (during step 2)
+#		usually precludes splicing of the connection at step 3.
+#
+#	    terminate
+#		Close client and server connections.
+#
+#	Backward compatibility actions available at step SslBump1:
+#
+#	    client-first
+#		Bump the connection. Establish a secure connection with the
+#		client first, then connect to the server. This old mode does
+#		not allow Squid to mimic server SSL certificate and does not
+#		work with intercepted SSL connections.
+#
+#	    server-first
+#		Bump the connection. Establish a secure connection with the
+#		server first, then establish a secure connection with the
+#		client, using a mimicked server certificate. Works with both
+#		CONNECT requests and intercepted SSL connections, but does
+#		not allow to make decisions based on SSL handshake info.
+#
+#	    peek-and-splice
+#		Decide whether to bump or splice the connection based on 
+#		client-to-squid and server-to-squid SSL hello messages.
+#		XXX: Remove.
+#
+#	    none
+#		Same as the "splice" action.
+#
+#	All ssl_bump rules are evaluated at each of the supported bumping
+#	steps.  Rules with actions that are impossible at the current step are
+#	ignored. The first matching ssl_bump action wins and is applied at the
+#	end of the current step. If no rules match, the splice action is used.
+#	See the at_step ACL for a list of the supported SslBump steps.
 #
-#	See also: http_port ssl-bump
-#   
 #	This clause supports both fast and slow acl types.
 #	See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
 #
+#	See also: http_port ssl-bump, https_port ssl-bump, and acl at_step.
+#
 #
-#	# Example: Bump all requests except those originating from localhost and 
-#	# those going to webax.com or example.com sites.
+#	# Example: Bump all TLS connections except those originating from
+#	# localhost or those going to example.com.
 #
-#	acl localhost src 127.0.0.1/32
-#	acl broken_sites dstdomain .webax.com
-#	acl broken_sites dstdomain .example.com
-#	ssl_bump deny localhost
-#	ssl_bump deny broken_sites
-#	ssl_bump allow all
+#	acl broken_sites ssl::server_name .example.com
+#	ssl_bump splice localhost
+#	ssl_bump splice broken_sites
+#	ssl_bump bump all
 #Default:
-# none
+# Become a TCP tunnel without decrypting proxied traffic.
 
 #  TAG: sslproxy_flags
 # Note: This option is only available if Squid is rebuilt with the
-#       --enable-ssl option
+#       --with-openssl
 #
 #	Various flags modifying the use of SSL while proxying https:// URLs:
 #	    DONT_VERIFY_PEER	Accept certificates that fail verification.
@@ -1553,16 +2376,16 @@ http_port 3128
 
 #  TAG: sslproxy_cert_error
 # Note: This option is only available if Squid is rebuilt with the
-#       --enable-ssl option
+#       --with-openssl
 #
 #	Use this ACL to bypass server certificate validation errors.
 #
 #	For example, the following lines will bypass all validation errors
-#	when talking to servers located at 172.16.0.0/16. All other
+#	when talking to servers for example.com. All other
 #	validation errors will result in ERR_SECURE_CONNECT_FAIL error.
 #
-#		acl BrokenServersAtTrustedIP dst 172.16.0.0/16
-#		sslproxy_cert_error allow BrokenServersAtTrustedIP
+#		acl BrokenButTrustedServers dstdomain example.com
+#		sslproxy_cert_error allow BrokenButTrustedServers
 #		sslproxy_cert_error deny all
 #
 #	This clause only supports fast acl types.
@@ -1570,19 +2393,107 @@ http_port 3128
 #	Using slow acl types may result in server crashes
 #
 #	Without this option, all server certificate validation errors
-#	terminate the transaction. Bypassing validation errors is dangerous
-#	because an error usually implies that the server cannot be trusted and
-#	the connection may be insecure.
+#	terminate the transaction to protect Squid and the client.
+#
+#	SQUID_X509_V_ERR_INFINITE_VALIDATION error cannot be bypassed
+#	but should not happen unless your OpenSSL library is buggy.
+#
+#	SECURITY WARNING:
+#		Bypassing validation errors is dangerous because an
+#		error usually implies that the server cannot be trusted
+#		and the connection may be insecure.
 #
 #	See also: sslproxy_flags and DONT_VERIFY_PEER.
+#Default:
+# Server certificate errors terminate the transaction.
+
+#  TAG: sslproxy_cert_sign
+# Note: This option is only available if Squid is rebuilt with the
+#       --with-openssl
+#
+#
+#        sslproxy_cert_sign <signing algorithm> acl ...
+#
+#        The following certificate signing algorithms are supported:
+#
+#	   signTrusted
+#		Sign using the configured CA certificate which is usually
+#		placed in and trusted by end-user browsers. This is the
+#		default for trusted origin server certificates.
 #
-#	Default setting:  sslproxy_cert_error deny all
+#	   signUntrusted
+#		Sign to guarantee an X509_V_ERR_CERT_UNTRUSTED browser error.
+#		This is the default for untrusted origin server certificates
+#		that are not self-signed (see ssl::certUntrusted).
+#
+#	   signSelf
+#		Sign using a self-signed certificate with the right CN to
+#		generate a X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT error in the
+#		browser. This is the default for self-signed origin server
+#		certificates (see ssl::certSelfSigned).
+#
+#	This clause only supports fast acl types.
+#
+#	When sslproxy_cert_sign acl(s) match, Squid uses the corresponding
+#	signing algorithm to generate the certificate and ignores all
+#	subsequent sslproxy_cert_sign options (the first match wins). If no
+#	acl(s) match, the default signing algorithm is determined by errors
+#	detected when obtaining and validating the origin server certificate.
+#
+#	WARNING: SQUID_X509_V_ERR_DOMAIN_MISMATCH and ssl:certDomainMismatch can
+#	be used with sslproxy_cert_adapt, but if and only if Squid is bumping a
+#	CONNECT request that carries a domain name. In all other cases (CONNECT
+#	to an IP address or an intercepted SSL connection), Squid cannot detect
+#	the domain mismatch at certificate generation time when
+#	bump-server-first is used.
+#Default:
+# none
+
+#  TAG: sslproxy_cert_adapt
+# Note: This option is only available if Squid is rebuilt with the
+#       --with-openssl
+#
+#	
+#	sslproxy_cert_adapt <adaptation algorithm> acl ...
+#
+#	The following certificate adaptation algorithms are supported:
+#
+#	   setValidAfter
+#		Sets the "Not After" property to the "Not After" property of
+#		the CA certificate used to sign generated certificates.
+#
+#	   setValidBefore
+#		Sets the "Not Before" property to the "Not Before" property of
+#		the CA certificate used to sign generated certificates.
+#
+#	   setCommonName or setCommonName{CN}
+#		Sets Subject.CN property to the host name specified as a 
+#		CN parameter or, if no explicit CN parameter was specified,
+#		extracted from the CONNECT request. It is a misconfiguration
+#		to use setCommonName without an explicit parameter for
+#		intercepted or tproxied SSL connections.
+#		
+#	This clause only supports fast acl types.
+#
+#	Squid first groups sslproxy_cert_adapt options by adaptation algorithm.
+#	Within a group, when sslproxy_cert_adapt acl(s) match, Squid uses the
+#	corresponding adaptation algorithm to generate the certificate and
+#	ignores all subsequent sslproxy_cert_adapt options in that algorithm's
+#	group (i.e., the first match wins within each algorithm group). If no
+#	acl(s) match, the default mimicking action takes place.
+#
+#	WARNING: SQUID_X509_V_ERR_DOMAIN_MISMATCH and ssl:certDomainMismatch can
+#	be used with sslproxy_cert_adapt, but if and only if Squid is bumping a
+#	CONNECT request that carries a domain name. In all other cases (CONNECT
+#	to an IP address or an intercepted SSL connection), Squid cannot detect
+#	the domain mismatch at certificate generation time when
+#	bump-server-first is used.
 #Default:
 # none
 
 #  TAG: sslpassword_program
 # Note: This option is only available if Squid is rebuilt with the
-#       --enable-ssl option
+#       --with-openssl
 #
 #	Specify a program used for entering SSL key passphrases
 #	when using encrypted SSL certificate keys. If not specified
@@ -1595,12 +2506,12 @@ http_port 3128
 #Default:
 # none
 
-#OPTIONS RELATING TO EXTERNAL SSL_CRTD 
-#-----------------------------------------------------------------------------
+# OPTIONS RELATING TO EXTERNAL SSL_CRTD 
+# -----------------------------------------------------------------------------
 
 #  TAG: sslcrtd_program
 # Note: This option is only available if Squid is rebuilt with the
-#       -DUSE_SSL_CRTD define
+#       --enable-ssl-crtd
 #
 #	Specify the location and options of the executable for ssl_crtd process.
 #	/usr/lib/squid/ssl_crtd program requires -s and -M parameters
@@ -1611,14 +2522,90 @@ http_port 3128
 
 #  TAG: sslcrtd_children
 # Note: This option is only available if Squid is rebuilt with the
-#       -DUSE_SSL_CRTD define
+#       --enable-ssl-crtd
 #
 #	The maximum number of processes spawn to service ssl server.
 #	The maximum this may be safely set to is 32.
 #	
+#	The startup= and idle= options allow some measure of skew in your
+#	tuning.
+#	
+#		startup=N
+#	
+#	Sets the minimum number of processes to spawn when Squid
+#	starts or reconfigures. When set to zero the first request will
+#	cause spawning of the first child process to handle it.
+#	
+#	Starting too few children temporary slows Squid under load while it
+#	tries to spawn enough additional processes to cope with traffic.
+#	
+#		idle=N
+#	
+#	Sets a minimum of how many processes Squid is to try and keep available
+#	at all times. When traffic begins to rise above what the existing
+#	processes can handle this many more will be spawned up to the maximum
+#	configured. A minimum setting of 1 is required.
+#	
 #	You must have at least one ssl_crtd process.
 #Default:
-# sslcrtd_children 5
+# sslcrtd_children 32 startup=5 idle=1
+
+#  TAG: sslcrtvalidator_program
+# Note: This option is only available if Squid is rebuilt with the
+#       --with-openssl
+#
+#	Specify the location and options of the executable for ssl_crt_validator
+#	process.
+#
+#	Usage:  sslcrtvalidator_program [ttl=n] [cache=n] path ...
+#
+#	Options:
+#	  ttl=n         TTL in seconds for cached results. The default is 60 secs
+#	  cache=n       limit the result cache size. The default value is 2048
+#Default:
+# none
+
+#  TAG: sslcrtvalidator_children
+# Note: This option is only available if Squid is rebuilt with the
+#       --with-openssl
+#
+#	The maximum number of processes spawn to service SSL server.
+#	The maximum this may be safely set to is 32.
+#	
+#	The startup= and idle= options allow some measure of skew in your
+#	tuning.
+#	
+#		startup=N
+#	
+#	Sets the minimum number of processes to spawn when Squid
+#	starts or reconfigures. When set to zero the first request will
+#	cause spawning of the first child process to handle it.
+#	
+#	Starting too few children temporary slows Squid under load while it
+#	tries to spawn enough additional processes to cope with traffic.
+#	
+#		idle=N
+#	
+#	Sets a minimum of how many processes Squid is to try and keep available
+#	at all times. When traffic begins to rise above what the existing
+#	processes can handle this many more will be spawned up to the maximum
+#	configured. A minimum setting of 1 is required.
+#
+#		concurrency=
+#	
+#	The number of requests each certificate validator helper can handle in
+#	parallel. A value of 0 indicates the certficate validator does not
+#	support concurrency. Defaults to 1.
+#	
+#	When this directive is set to a value >= 1 then the protocol
+#	used to communicate with the helper is modified to include
+#	a request ID in front of the request/response. The request
+#	ID from the request must be echoed back with the response
+#	to that request.
+#	
+#	You must have at least one ssl_crt_validator process.
+#Default:
+# sslcrtvalidator_children 32 startup=5 idle=1 concurrency=1
 
 # OPTIONS WHICH AFFECT THE NEIGHBOR SELECTION ALGORITHM
 # -----------------------------------------------------------------------------
@@ -1680,22 +2667,23 @@ http_port 3128
 #	
 #	htcp		Send HTCP, instead of ICP, queries to the neighbor.
 #			You probably also want to set the "icp-port" to 4827
-#			instead of 3130.
+#			instead of 3130. This directive accepts a comma separated
+#			list of options described below.
 #	
-#	htcp-oldsquid	Send HTCP to old Squid versions.
+#	htcp=oldsquid	Send HTCP to old Squid versions (2.5 or earlier).
 #	
-#	htcp-no-clr	Send HTCP to the neighbor but without
+#	htcp=no-clr	Send HTCP to the neighbor but without
 #			sending any CLR requests.  This cannot be used with
-#			htcp-only-clr.
+#			only-clr.
 #	
-#	htcp-only-clr	Send HTCP to the neighbor but ONLY CLR requests.
-#			This cannot be used with htcp-no-clr.
+#	htcp=only-clr	Send HTCP to the neighbor but ONLY CLR requests.
+#			This cannot be used with no-clr.
 #	
-#	htcp-no-purge-clr
+#	htcp=no-purge-clr
 #			Send HTCP to the neighbor including CLRs but only when
 #			they do not result from PURGE requests.
 #	
-#	htcp-forward-clr
+#	htcp=forward-clr
 #			Forward any HTCP CLR requests this proxy receives to the peer.
 #	
 #	
@@ -1768,6 +2756,14 @@ http_port 3128
 #			than the Squid default location.
 #	
 #	
+#	==== CARP OPTIONS ====
+#	
+#	carp-key=key-specification
+#			use a different key than the full URL to hash against the peer.
+#			the key-specification is a comma-separated list of the keywords			
+#			scheme, host, port, path, params
+#			Order is not important.
+#	
 #	==== ACCELERATOR / REVERSE-PROXY OPTIONS ====
 #	
 #	originserver	Causes this parent to be contacted as an origin server.
@@ -1795,20 +2791,23 @@ http_port 3128
 #			Note: The string can include URL escapes (i.e. %20 for
 #			spaces). This also means % must be written as %%.
 #	
-#	login=PROXYPASS
+#	login=PASSTHRU
 #			Send login details received from client to this peer.
-#			Authentication is not required, nor changed.
+#			Both Proxy- and WWW-Authorization headers are passed
+#			without alteration to the peer.
+#			Authentication is not required by Squid for this to work.
 #			
 #			Note: This will pass any form of authentication but
 #			only Basic auth will work through a proxy unless the
 #			connection-auth options are also used.
-#	
+#
 #	login=PASS	Send login details received from client to this peer.
 #			Authentication is not required by this option.
+#			
 #			If there are no client-provided authentication headers
 #			to pass on, but username and password are available
-#			from either proxy login or an external ACL user= and
-#			password= result tags they may be sent instead.
+#			from an external ACL user= and password= result tags
+#			they may be sent instead.
 #			
 #			Note: To combine this with proxy_auth both proxies must
 #			share the same user database as HTTP only allows for
@@ -1826,6 +2825,27 @@ http_port 3128
 #			be used to identify this proxy to the peer, similar to
 #			the login=username:password option above.
 #	
+#	login=NEGOTIATE
+#			If this is a personal/workgroup proxy and your parent
+#			requires a secure proxy authentication.
+#			The first principal from the default keytab or defined by
+#			the environment variable KRB5_KTNAME will be used. 
+#	
+#			WARNING: The connection may transmit requests from multiple
+#			clients. Negotiate often assumes end-to-end authentication
+#			and a single-client. Which is not strictly true here.
+#	
+#	login=NEGOTIATE:principal_name
+#			If this is a personal/workgroup proxy and your parent
+#			requires a secure proxy authentication. 
+#			The principal principal_name from the default keytab or
+#			defined by the environment variable KRB5_KTNAME will be
+#			used.
+#	
+#			WARNING: The connection may transmit requests from multiple
+#			clients. Negotiate often assumes end-to-end authentication
+#			and a single-client. Which is not strictly true here.
+#	
 #	connection-auth=on|off
 #			Tell Squid that this peer does or not support Microsoft
 #			connection oriented authentication, and any such
@@ -1848,22 +2868,42 @@ http_port 3128
 #			reference a combined file containing both the
 #			certificate and the key.
 #	
-#	sslversion=1|2|3|4
+#	sslversion=1|2|3|4|5|6
 #			The SSL version to use when connecting to this peer
 #				1 = automatic (default)
 #				2 = SSL v2 only
 #				3 = SSL v3 only
-#				4 = TLS v1 only
+#				4 = TLS v1.0 only
+#				5 = TLS v1.1 only
+#				6 = TLS v1.2 only
 #	
 #	sslcipher=...	The list of valid SSL ciphers to use when connecting
 #			to this peer.
 #	
-#	ssloptions=... 	Specify various SSL engine options:
-#				NO_SSLv2  Disallow the use of SSLv2
-#				NO_SSLv3  Disallow the use of SSLv3
-#				NO_TLSv1  Disallow the use of TLSv1
-#			See src/ssl_support.c or the OpenSSL documentation for
-#			a more complete list.
+#	ssloptions=... 	Specify various SSL implementation options:
+#
+#			    NO_SSLv2    Disallow the use of SSLv2
+#			    NO_SSLv3    Disallow the use of SSLv3
+#			    NO_TLSv1    Disallow the use of TLSv1.0
+#			    NO_TLSv1_1  Disallow the use of TLSv1.1
+#			    NO_TLSv1_2  Disallow the use of TLSv1.2
+#
+#			    SINGLE_DH_USE
+#				      Always create a new key when using
+#				      temporary/ephemeral DH key exchanges
+#
+#			    NO_TICKET
+#				      Disable use of RFC5077 session tickets. Some servers
+#				      may have problems understanding the TLS extension due
+#				      to ambiguous specification in RFC4507.
+#
+#			    ALL       Enable various bug workarounds
+#				      suggested as "harmless" by OpenSSL
+#				      Be warned that this reduces SSL/TLS
+#				      strength to some attacks.
+#
+#			See the OpenSSL SSL_CTX_set_options documentation for a
+#			more complete list.
 #	
 #	sslcafile=... 	A file containing additional CA certificates to use
 #			when verifying the peer certificate.
@@ -1907,29 +2947,74 @@ http_port 3128
 #	
 #	connect-fail-limit=N
 #			How many times connecting to a peer must fail before
-#			it is marked as down. Default is 10.
+#			it is marked as down. Standby connection failures
+#			count towards this limit. Default is 10.
 #	
 #	allow-miss	Disable Squid's use of only-if-cached when forwarding
 #			requests to siblings. This is primarily useful when
-#			icp_hit_stale is used by the sibling. To extensive use
-#			of this option may result in forwarding loops, and you
-#			should avoid having two-way peerings with this option.
-#			For example to deny peer usage on requests from peer
-#			by denying cache_peer_access if the source is a peer.
+#			icp_hit_stale is used by the sibling. Excessive use
+#			of this option may result in forwarding loops. One way
+#			to prevent peering loops when using this option, is to
+#			deny cache peer usage on requests from a peer:
+#			acl fromPeer ...
+#			cache_peer_access peerName deny fromPeer
+#	
+#	max-conn=N 	Limit the number of concurrent connections the Squid
+#			may open to this peer, including already opened idle
+#			and standby connections. There is no peer-specific
+#			connection limit by default.
+#	
+#			A peer exceeding the limit is not used for new
+#			requests unless a standby connection is available.
 #	
-#	max-conn=N	Limit the amount of connections Squid may open to this
-#			peer. see also 
+#			max-conn currently works poorly with idle persistent
+#			connections: When a peer reaches its max-conn limit,
+#			and there are idle persistent connections to the peer,
+#			the peer may not be selected because the limiting code
+#			does not know whether Squid can reuse those idle
+#			connections.
+#	
+#	standby=N	Maintain a pool of N "hot standby" connections to an
+#			UP peer, available for requests when no idle
+#			persistent connection is available (or safe) to use.
+#			By default and with zero N, no such pool is maintained.
+#			N must not exceed the max-conn limit (if any).
+#	
+#			At start or after reconfiguration, Squid opens new TCP
+#			standby connections until there are N connections
+#			available and then replenishes the standby pool as
+#			opened connections are used up for requests. A used
+#			connection never goes back to the standby pool, but
+#			may go to the regular idle persistent connection pool
+#			shared by all peers and origin servers.
+#	
+#			Squid never opens multiple new standby connections
+#			concurrently.  This one-at-a-time approach minimizes
+#			flooding-like effect on peers. Furthermore, just a few
+#			standby connections should be sufficient in most cases
+#			to supply most new requests with a ready-to-use
+#			connection.
+#	
+#			Standby connections obey server_idle_pconn_timeout.
+#			For the feature to work as intended, the peer must be
+#			configured to accept and keep them open longer than
+#			the idle timeout at the connecting Squid, to minimize
+#			race conditions typical to idle used persistent
+#			connections. Default request_timeout and
+#			server_idle_pconn_timeout values ensure such a
+#			configuration.
 #	
 #	name=xxx	Unique name for the peer.
 #			Required if you have multiple peers on the same host
 #			but different ports.
 #			This name can be used in cache_peer_access and similar
-#			directives to dentify the peer.
+#			directives to identify the peer.
 #			Can be used by outgoing access controls through the
 #			peername ACL type.
 #	
 #	no-tproxy	Do not use the client-spoof TPROXY support when forwarding
 #			requests to this peer. Use normal address selection instead.
+#			This overrides the spoof_client_ip ACL.
 #	
 #	proxy-only	objects fetched from the peer will not be stored locally.
 #	
@@ -1938,10 +3023,11 @@ http_port 3128
 
 #  TAG: cache_peer_domain
 #	Use to limit the domains for which a neighbor cache will be
-#	queried.  Usage:
+#	queried.
 #
-#	cache_peer_domain cache-host domain [domain ...]
-#	cache_peer_domain cache-host !domain
+#	Usage:
+#		cache_peer_domain cache-host domain [domain ...]
+#		cache_peer_domain cache-host !domain
 #
 #	For example, specifying
 #
@@ -1966,33 +3052,57 @@ http_port 3128
 # none
 
 #  TAG: cache_peer_access
-#	Similar to 'cache_peer_domain' but provides more flexibility by
-#	using ACL elements.
+#	Restricts usage of cache_peer proxies.
 #
-#	cache_peer_access cache-host allow|deny [!]aclname ...
+#	Usage:
+#		cache_peer_access peer-name allow|deny [!]aclname ...
+#
+#	For the required peer-name parameter, use either the value of the
+#	cache_peer name=value parameter or, if name=value is missing, the
+#	cache_peer hostname parameter.
+#
+#	This directive narrows down the selection of peering candidates, but
+#	does not determine the order in which the selected candidates are
+#	contacted. That order is determined by the peer selection algorithms
+#	(see PEER SELECTION sections in the cache_peer documentation).
+#
+#	If a deny rule matches, the corresponding peer will not be contacted
+#	for the current transaction -- Squid will not send ICP queries and
+#	will not forward HTTP requests to that peer. An allow match leaves
+#	the corresponding peer in the selection. The first match for a given
+#	peer wins for that peer.
+#
+#	The relative order of cache_peer_access directives for the same peer
+#	matters. The relative order of any two cache_peer_access directives
+#	for different peers does not matter. To ease interpretation, it is a
+#	good idea to group cache_peer_access directives for the same peer
+#	together.
+#
+#	A single cache_peer_access directive may be evaluated multiple times
+#	for a given transaction because individual peer selection algorithms
+#	may check it independently from each other. These redundant checks
+#	may be optimized away in future Squid versions.
 #
-#	The syntax is identical to 'http_access' and the other lists of
-#	ACL elements.  See the comments for 'http_access' below, or
-#	the Squid FAQ (http://wiki.squid-cache.org/SquidFaq/SquidAcl).
+#	This clause only supports fast acl types.
+#	See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
 #Default:
-# none
+# No peer usage restrictions.
 
 #  TAG: neighbor_type_domain
-#	usage: neighbor_type_domain neighbor parent|sibling domain domain ...
+#	Modify the cache_peer neighbor type when passing requests
+#	about specific domains to the peer.
 #
-#	Modifying the neighbor type for specific domains is now
-#	possible.  You can treat some domains differently than the the
-#	default neighbor type specified on the 'cache_peer' line.
-#	Normally it should only be necessary to list domains which
-#	should be treated differently because the default neighbor type
-#	applies for hostnames which do not match domains listed here.
+#	Usage:
+#		 neighbor_type_domain neighbor parent|sibling domain domain ...
 #
-#EXAMPLE:
-#	cache_peer cache.foo.org parent 3128 3130
-#	neighbor_type_domain cache.foo.org sibling .com .net
-#	neighbor_type_domain cache.foo.org sibling .au .de
+#	For example:
+#		cache_peer foo.example.com parent 3128 3130
+#		neighbor_type_domain foo.example.com sibling .au .de
+#
+#	The above configuration treats all requests to foo.example.com as a
+#	parent proxy unless the request is for a .au or .de ccTLD domain name.
 #Default:
-# none
+# The peer type from cache_peer directive is used for all requests to that peer.
 
 #  TAG: dead_peer_timeout	(seconds)
 #	This controls how long Squid waits to declare a peer cache
@@ -2015,21 +3125,11 @@ http_port 3128
 #  TAG: forward_max_tries
 #	Controls how many different forward paths Squid will try
 #	before giving up. See also forward_timeout.
+#	
+#	NOTE: connect_retries (default: none) can make each of these
+#	possible forwarding paths be tried multiple times.
 #Default:
-# forward_max_tries 10
-
-#  TAG: hierarchy_stoplist
-#	A list of words which, if found in a URL, cause the object to
-#	be handled directly by this cache.  In other words, use this
-#	to not query neighbor caches for certain objects.  You may
-#	list this option multiple times.
-#
-#	Example:
-#		hierarchy_stoplist cgi-bin ?
-#
-#	Note: never_direct overrides this option.
-#Default:
-# none
+# forward_max_tries 25
 
 # MEMORY CACHE OPTIONS
 # -----------------------------------------------------------------------------
@@ -2064,6 +3164,11 @@ http_port 3128
 #	decreases, blocks will be freed until the high-water mark is
 #	reached.  Thereafter, blocks will be used to store hot
 #	objects.
+#
+#	If shared memory caching is enabled, Squid does not use the shared
+#	cache space for in-transit objects, but they still consume as much
+#	local memory as they need. For more details about the shared memory
+#	cache, see memory_cache_shared.
 #Default:
 # cache_mem 256 MB
 
@@ -2075,11 +3180,45 @@ http_port 3128
 #Default:
 # maximum_object_size_in_memory 512 KB
 
+#  TAG: memory_cache_shared	on|off
+#	Controls whether the memory cache is shared among SMP workers.
+#
+#	The shared memory cache is meant to occupy cache_mem bytes and replace
+#	the non-shared memory cache, although some entities may still be
+#	cached locally by workers for now (e.g., internal and in-transit
+#	objects may be served from a local memory cache even if shared memory
+#	caching is enabled).
+#
+#	By default, the memory cache is shared if and only if all of the
+#	following conditions are satisfied: Squid runs in SMP mode with
+#	multiple workers, cache_mem is positive, and Squid environment
+#	supports required IPC primitives (e.g., POSIX shared memory segments
+#	and GCC-style atomic operations).
+#
+#	To avoid blocking locks, shared memory uses opportunistic algorithms
+#	that do not guarantee that every cachable entity that could have been
+#	shared among SMP workers will actually be shared.
+#Default:
+# "on" where supported if doing memory caching with multiple SMP workers.
+
+#  TAG: memory_cache_mode
+#	Controls which objects to keep in the memory cache (cache_mem)
+#
+#	always	Keep most recently fetched objects in memory (default)
+#
+#	disk	Only disk cache hits are kept in memory, which means
+#		an object must first be cached on disk and then hit
+#		a second time before cached in memory.
+#
+#	network	Only objects fetched from network is kept in memory
+#Default:
+# Keep the most recently fetched objects in memory
+
 #  TAG: memory_replacement_policy
 #	The memory replacement policy parameter determines which
 #	objects are purged from memory when memory space is needed.
 #
-#	See cache_replacement_policy for details.
+#	See cache_replacement_policy for details on algorithms.
 #Default:
 # memory_replacement_policy lru
 
@@ -2095,7 +3234,7 @@ http_port 3128
 #	    heap LFUDA: Least Frequently Used with Dynamic Aging
 #	    heap LRU  : LRU policy implemented using a heap
 #
-#	Applies to any cache_dir lines listed below this.
+#	Applies to any cache_dir lines listed below this directive.
 #
 #	The LRU policies keeps recently referenced objects.
 #
@@ -2114,7 +3253,7 @@ http_port 3128
 #	replacement policies.
 #
 #	NOTE: if using the LFUDA replacement policy you should increase
-#	the value of maximum_object_size above its default of 4096 KB to
+#	the value of maximum_object_size above its default of 4 MB to
 #	to maximize the potential byte hit rate improvement of LFUDA.
 #
 #	For more information about the GDSF and LFUDA cache replacement
@@ -2123,10 +3262,34 @@ http_port 3128
 #Default:
 # cache_replacement_policy lru
 
+#  TAG: minimum_object_size	(bytes)
+#	Objects smaller than this size will NOT be saved on disk.  The
+#	value is specified in bytes, and the default is 0 KB, which
+#	means all responses can be stored.
+#Default:
+# no limit
+
+#  TAG: maximum_object_size	(bytes)
+#	Set the default value for max-size parameter on any cache_dir.
+#	The value is specified in bytes, and the default is 4 MB.
+#	
+#	If you wish to get a high BYTES hit ratio, you should probably
+#	increase this (one 32 MB object hit counts for 3200 10KB
+#	hits).
+#	
+#	If you wish to increase hit ratio more than you want to
+#	save bandwidth you should leave this low.
+#	
+#	NOTE: if using the LFUDA replacement policy you should increase
+#	this value to maximize the byte hit rate improvement of LFUDA!
+#	See cache_replacement_policy for a discussion of this policy.
+#Default:
+# maximum_object_size 4 MB
+maximum_object_size 153600 KB
+
 #  TAG: cache_dir
-#	Usage:
-#
-#	cache_dir Type Directory-Name Fs-specific-data [options]
+#	Format:
+#		cache_dir Type Directory-Name Fs-specific-data [options]
 #
 #	You can specify multiple cache_dir lines to spread the
 #	cache among different disk partitions.
@@ -2141,12 +3304,18 @@ http_port 3128
 #	The directory must exist and be writable by the Squid
 #	process.  Squid will NOT create this directory for you.
 #
-#	The ufs store type:
+#	In SMP configurations, cache_dir must not precede the workers option
+#	and should use configuration macros or conditionals to give each
+#	worker interested in disk caching a dedicated cache directory.
+#
+#
+#	====  The ufs store type  ====
 #
 #	"ufs" is the old well-known Squid storage format that has always
 #	been there.
 #
-#	cache_dir ufs Directory-Name Mbytes L1 L2 [options]
+#	Usage:
+#		cache_dir ufs Directory-Name Mbytes L1 L2 [options]
 #
 #	'Mbytes' is the amount of disk space (MB) to use under this
 #	directory.  The default is 100 MB.  Change this to suit your
@@ -2161,23 +3330,27 @@ http_port 3128
 #	will be created under each first-level directory.  The default
 #	is 256.
 #
-#	The aufs store type:
+#
+#	====  The aufs store type  ====
 #
 #	"aufs" uses the same storage format as "ufs", utilizing
 #	POSIX-threads to avoid blocking the main Squid process on
 #	disk-I/O. This was formerly known in Squid as async-io.
 #
-#	cache_dir aufs Directory-Name Mbytes L1 L2 [options]
+#	Usage:
+#		cache_dir aufs Directory-Name Mbytes L1 L2 [options]
 #
 #	see argument descriptions under ufs above
 #
-#	The diskd store type:
+#
+#	====  The diskd store type  ====
 #
 #	"diskd" uses the same storage format as "ufs", utilizing a
 #	separate process to avoid blocking the main Squid process on
 #	disk-I/O.
 #
-#	cache_dir diskd Directory-Name Mbytes L1 L2 [options] [Q1=n] [Q2=n]
+#	Usage:
+#		cache_dir diskd Directory-Name Mbytes L1 L2 [options] [Q1=n] [Q2=n]
 #
 #	see argument descriptions under ufs above
 #
@@ -2195,37 +3368,78 @@ http_port 3128
 #	higher hit ratio at the expense of an increase in response
 #	time.
 #
-#	The coss store type:
-#
-#	NP: COSS filesystem in Squid-3 has been deemed too unstable for
-#	    production use and has thus been removed from this release.
-#	    We hope that it can be made usable again soon.
-#
-#	block-size=n defines the "block size" for COSS cache_dir's.
-#	Squid uses file numbers as block numbers.  Since file numbers
-#	are limited to 24 bits, the block size determines the maximum
-#	size of the COSS partition.  The default is 512 bytes, which
-#	leads to a maximum cache_dir size of 512<<24, or 8 GB.  Note
-#	you should not change the coss block size after Squid
-#	has written some objects to the cache_dir.
 #
-#	The coss file store has changed from 2.5. Now it uses a file
-#	called 'stripe' in the directory names in the config - and
-#	this will be created by squid -z.
+#	====  The rock store type  ====
 #
-#	Common options:
-#
-#	no-store, no new objects should be stored to this cache_dir
+#	Usage:
+#	    cache_dir rock Directory-Name Mbytes [options]
+#
+#	The Rock Store type is a database-style storage. All cached
+#	entries are stored in a "database" file, using fixed-size slots.
+#	A single entry occupies one or more slots.
+#
+#	If possible, Squid using Rock Store creates a dedicated kid
+#	process called "disker" to avoid blocking Squid worker(s) on disk
+#	I/O. One disker kid is created for each rock cache_dir.  Diskers
+#	are created only when Squid, running in daemon mode, has support
+#	for the IpcIo disk I/O module.
+#
+#	swap-timeout=msec: Squid will not start writing a miss to or
+#	reading a hit from disk if it estimates that the swap operation
+#	will take more than the specified number of milliseconds. By
+#	default and when set to zero, disables the disk I/O time limit
+#	enforcement. Ignored when using blocking I/O module because
+#	blocking synchronous I/O does not allow Squid to estimate the
+#	expected swap wait time.
+#
+#	max-swap-rate=swaps/sec: Artificially limits disk access using
+#	the specified I/O rate limit. Swap out requests that
+#	would cause the average I/O rate to exceed the limit are
+#	delayed. Individual swap in requests (i.e., hits or reads) are
+#	not delayed, but they do contribute to measured swap rate and
+#	since they are placed in the same FIFO queue as swap out
+#	requests, they may wait longer if max-swap-rate is smaller.
+#	This is necessary on file systems that buffer "too
+#	many" writes and then start blocking Squid and other processes
+#	while committing those writes to disk.  Usually used together
+#	with swap-timeout to avoid excessive delays and queue overflows
+#	when disk demand exceeds available disk "bandwidth". By default
+#	and when set to zero, disables the disk I/O rate limit
+#	enforcement. Currently supported by IpcIo module only.
+#
+#	slot-size=bytes: The size of a database "record" used for
+#	storing cached responses. A cached response occupies at least
+#	one slot and all database I/O is done using individual slots so
+#	increasing this parameter leads to more disk space waste while
+#	decreasing it leads to more disk I/O overheads. Should be a
+#	multiple of your operating system I/O page size. Defaults to
+#	16KBytes. A housekeeping header is stored with each slot and
+#	smaller slot-sizes will be rejected. The header is smaller than
+#	100 bytes.
+#
+#
+#	==== COMMON OPTIONS ====
+#
+#	no-store	no new objects should be stored to this cache_dir.
+#
+#	min-size=n	the minimum object size in bytes this cache_dir
+#			will accept.  It's used to restrict a cache_dir
+#			to only store large objects (e.g. AUFS) while
+#			other stores are optimized for smaller objects
+#			(e.g. Rock).
+#			Defaults to 0.
+#
+#	max-size=n	the maximum object size in bytes this cache_dir
+#			supports.
+#			The value in maximum_object_size directive sets
+#			the default unless more specific details are
+#			available (ie a small store capacity).
 #
-#	max-size=n, refers to the max object size in bytes this cache_dir
-#	supports.  It is used to select the cache_dir to store the object.
 #	Note: To make optimal use of the max-size limits you should order
-#	the cache_dir lines with the smallest max-size value first and the
-#	ones with no max-size specification last.
+#	the cache_dir lines with the smallest max-size value first.
 #
-#	Note for coss, max-size must be less than COSS_MEMBUF_SZ,
-#	which can be changed with the --with-coss-membuf-size=N configure
-#	option.
+#Default:
+# No disk cache. Store cache ojects only in memory.
 #
 
 # Uncomment and adjust the following to add a disk cache directory.
@@ -2233,7 +3447,60 @@ http_port 3128
 cache_dir ufs /var/spool/squid 4096 16 1024
 
 #  TAG: store_dir_select_algorithm
-#	Set this to 'round-robin' as an alternative.
+#	How Squid selects which cache_dir to use when the response
+#	object will fit into more than one.
+#
+#	Regardless of which algorithm is used the cache_dir min-size
+#	and max-size parameters are obeyed. As such they can affect
+#	the selection algorithm by limiting the set of considered
+#	cache_dir.
+#
+#	Algorithms:
+#
+#		least-load
+#
+#	This algorithm is suited to caches with similar cache_dir
+#	sizes and disk speeds.
+#
+#	The disk with the least I/O pending is selected.
+#	When there are multiple disks with the same I/O load ranking
+#	the cache_dir with most available capacity is selected.
+#
+#	When a mix of cache_dir sizes are configured the faster disks
+#	have a naturally lower I/O loading and larger disks have more
+#	capacity. So space used to store objects and data throughput
+#	may be very unbalanced towards larger disks.
+#
+#
+#		round-robin
+#
+#	This algorithm is suited to caches with unequal cache_dir
+#	disk sizes.
+#
+#	Each cache_dir is selected in a rotation. The next suitable
+#	cache_dir is used.
+#
+#	Available cache_dir capacity is only considered in relation
+#	to whether the object will fit and meets the min-size and
+#	max-size parameters.
+#
+#	Disk I/O loading is only considered to prevent overload on slow
+#	disks. This algorithm does not spread objects by size, so any
+#	I/O loading per-disk may appear very unbalanced and volatile.
+#
+#	If several cache_dirs use similar min-size, max-size, or other
+#	limits to to reject certain responses, then do not group such
+#	cache_dir lines together, to avoid round-robin selection bias
+#	towards the first cache_dir after the group. Instead, interleave
+#	cache_dir lines from different groups. For example:
+#
+#		store_dir_select_algorithm round-robin
+#		cache_dir rock /hdd1 ... min-size=100000
+#		cache_dir rock /ssd1 ... max-size=99999
+#		cache_dir rock /hdd2 ... min-size=100000
+#		cache_dir rock /ssd2 ... max-size=99999
+#		cache_dir rock /hdd3 ... min-size=100000
+#		cache_dir rock /ssd3 ... max-size=99999
 #Default:
 # store_dir_select_algorithm least-load
 
@@ -2244,46 +3511,53 @@ cache_dir ufs /var/spool/squid 4096 16 1024
 #
 #	A value of 0 indicates no limit.
 #Default:
-# max_open_disk_fds 0
-
-#  TAG: minimum_object_size	(bytes)
-#	Objects smaller than this size will NOT be saved on disk.  The
-#	value is specified in kilobytes, and the default is 0 KB, which
-#	means there is no minimum.
-#Default:
-# minimum_object_size 0 KB
-
-#  TAG: maximum_object_size	(bytes)
-#	Objects larger than this size will NOT be saved on disk.  The
-#	value is specified in kilobytes, and the default is 4MB.  If
-#	you wish to get a high BYTES hit ratio, you should probably
-#	increase this (one 32 MB object hit counts for 3200 10KB
-#	hits).  If you wish to increase speed more than your want to
-#	save bandwidth you should leave this low.
-#
-#	NOTE: if using the LFUDA replacement policy you should increase
-#	this value to maximize the byte hit rate improvement of LFUDA!
-#	See replacement_policy below for a discussion of this policy.
-#Default:
-# maximum_object_size 4096 KB
-maximum_object_size 153600 KB
+# no limit
 
 #  TAG: cache_swap_low	(percent, 0-100)
+#	The low-water mark for AUFS/UFS/diskd cache object eviction by
+#	the cache_replacement_policy algorithm.
+#
+#	Removal begins when the swap (disk) usage of a cache_dir is
+#	above this low-water mark and attempts to maintain utilization
+#	near the low-water mark.
+#
+#	As swap utilization increases towards the high-water mark set
+#	by cache_swap_high object eviction becomes more agressive.
+#
+#	The value difference in percentages between low- and high-water
+#	marks represent an eviction rate of 300 objects per second and
+#	the rate continues to scale in agressiveness by multiples of
+#	this above the high-water mark.
+#
+#	Defaults are 90% and 95%. If you have a large cache, 5% could be
+#	hundreds of MB. If this is the case you may wish to set these
+#	numbers closer together.
+#
+#	See also cache_swap_high and cache_replacement_policy
 #Default:
 # cache_swap_low 90
 
 #  TAG: cache_swap_high	(percent, 0-100)
+#	The high-water mark for AUFS/UFS/diskd cache object eviction by
+#	the cache_replacement_policy algorithm.
+#
+#	Removal begins when the swap (disk) usage of a cache_dir is
+#	above the low-water mark set by cache_swap_low and attempts to
+#	maintain utilization near the low-water mark.
 #
-#	The low- and high-water marks for cache object replacement.
-#	Replacement begins when the swap (disk) usage is above the
-#	low-water mark and attempts to maintain utilization near the
-#	low-water mark.  As swap utilization gets close to high-water
-#	mark object eviction becomes more aggressive.  If utilization is
-#	close to the low-water mark less replacement is done each time.
+#	As swap utilization increases towards this high-water mark object
+#	eviction becomes more agressive.
+#
+#	The value difference in percentages between low- and high-water
+#	marks represent an eviction rate of 300 objects per second and
+#	the rate continues to scale in agressiveness by multiples of
+#	this above the high-water mark.
 #
 #	Defaults are 90% and 95%. If you have a large cache, 5% could be
 #	hundreds of MB. If this is the case you may wish to set these
 #	numbers closer together.
+#
+#	See also cache_swap_low and cache_replacement_policy
 #Default:
 # cache_swap_high 95
 
@@ -2313,21 +3587,62 @@ maximum_object_size 153600 KB
 #		'	output as-is
 #
 #		-	left aligned
-#		width	field width. If starting with 0 the
-#			output is zero padded
+#
+#		width	minimum and/or maximum field width:
+#			    [width_min][.width_max]
+#			When minimum starts with 0, the field is zero-padded.
+#			String values exceeding maximum width are truncated.
+#
 #		{arg}	argument such as header name etc
 #
 #	Format codes:
 #
 #		%	a literal % character
+#		sn	Unique sequence number per log line entry
+#		err_code    The ID of an error response served by Squid or
+#				a similar internal error identifier.
+#		err_detail  Additional err_code-dependent error information.
+#		note	The annotation specified by the argument. Also
+#			logs the adaptation meta headers set by the
+#			adaptation_meta configuration parameter.
+#			If no argument given all annotations logged.
+#			The argument may include a separator to use with
+#			annotation values:
+#                            name[:separator]
+#			By default, multiple note values are separated with ","
+#			and multiple notes are separated with "\r\n".
+#			When logging named notes with %{name}note, the
+#			explicitly configured separator is used between note
+#			values. When logging all notes with %note, the
+#			explicitly configured separator is used between
+#			individual notes. There is currently no way to
+#			specify both value and notes separators when logging
+#			all notes with %note.
+#
+#	Connection related format codes:
+#
 #		>a	Client source IP address
 #		>A	Client FQDN
 #		>p	Client source port
-#		<A	Server IP address or peer name
-#		la	Local IP address (http_port)
-#		lp	Local port number (http_port)
+#		>eui	Client source EUI (MAC address, EUI-48 or EUI-64 identifier)
+#		>la	Local IP address the client connected to
+#		>lp	Local port number the client connected to
+#		>qos    Client connection TOS/DSCP value set by Squid
+#		>nfmark Client connection netfilter mark set by Squid
+#
+#		la	Local listening IP address the client connection was connected to.
+#		lp	Local listening port number the client connection was connected to.
+#
+#		<a	Server IP address of the last server or peer connection
+#		<A	Server FQDN or peer name
+#		<p	Server port number of the last server or peer connection
 #		<la	Local IP address of the last server or peer connection
 #		<lp     Local port number of the last server or peer connection
+#		<qos	Server connection TOS/DSCP value set by Squid
+#		<nfmark Server connection netfilter mark set by Squid
+#
+#	Time related format codes:
+#
 #		ts	Seconds since epoch
 #		tu	subsecond time (milliseconds)
 #		tl	Local time. Optional strftime format argument
@@ -2336,49 +3651,141 @@ maximum_object_size 153600 KB
 #				default %d/%b/%Y:%H:%M:%S %z
 #		tr	Response time (milliseconds)
 #		dt	Total time spent making DNS lookups (milliseconds)
+#		tS	Approximate master transaction start time in 
+#			<full seconds since epoch>.<fractional seconds> format.
+#			Currently, Squid considers the master transaction
+#			started when a complete HTTP request header initiating
+#			the transaction is received from the client. This is
+#			the same value that Squid uses to calculate transaction
+#			response time when logging %tr to access.log. Currently,
+#			Squid uses millisecond resolution for %tS values,
+#			similar to the default access.log "current time" field
+#			(%ts.%03tu).
+#
+#	Access Control related format codes:
+#
+#		et	Tag returned by external acl
+#		ea	Log string returned by external acl
+#		un	User name (any available)
+#		ul	User name from authentication
+#		ue	User name from external acl helper
+#		ui	User name from ident
+#		un	A user name. Expands to the first available name
+#			from the following list of information sources:
+#			- authenticated user name, like %ul
+#			- user name supplied by an external ACL, like %ue
+#			- SSL client name, like %us
+#			- ident user name, like %ui
+#		credentials Client credentials. The exact meaning depends on
+#			the authentication scheme: For Basic authentication,
+#			it is the password; for Digest, the realm sent by the
+#			client; for NTLM and Negotiate, the client challenge
+#			or client credentials prefixed with "YR " or "KK ".
+#
+#	HTTP related format codes:
+#
+#	    REQUEST
 #
-#	HTTP cache related format codes:
-#
-#		[http::]>h	Original request header. Optional header name argument
-#				on the format header[:[separator]element]
-#		[http::]>ha	The HTTP request headers after adaptation and redirection. 
+#		[http::]rm	Request method (GET/POST etc)
+#		[http::]>rm	Request method from client
+#		[http::]<rm	Request method sent to server or peer
+#		[http::]ru	Request URL from client (historic, filtered for logging)
+#		[http::]>ru	Request URL from client
+#		[http::]<ru	Request URL sent to server or peer
+#		[http::]>rs	Request URL scheme from client
+#		[http::]<rs	Request URL scheme sent to server or peer
+#		[http::]>rd	Request URL domain from client
+#		[http::]<rd	Request URL domain sent to server or peer
+#		[http::]>rP	Request URL port from client
+#		[http::]<rP	Request URL port sent to server or peer
+#		[http::]rp	Request URL path excluding hostname
+#		[http::]>rp	Request URL path excluding hostname from client
+#		[http::]<rp	Request URL path excluding hostname sent to server or peer
+#		[http::]rv	Request protocol version
+#		[http::]>rv	Request protocol version from client
+#		[http::]<rv	Request protocol version sent to server or peer
+#
+#		[http::]>h	Original received request header.
+#				Usually differs from the request header sent by
+#				Squid, although most fields are often preserved.
+#				Accepts optional header field name/value filter
+#				argument using name[:[separator]element] format.
+#		[http::]>ha	Received request header after adaptation and
+#				redirection (pre-cache REQMOD vectoring point).
+#				Usually differs from the request header sent by
+#				Squid, although most fields are often preserved.
 #				Optional header name argument as for >h
+#
+#
+#	    RESPONSE
+#
+#		[http::]<Hs	HTTP status code received from the next hop
+#		[http::]>Hs	HTTP status code sent to the client
+#
 #		[http::]<h	Reply header. Optional header name argument
 #				as for >h
-#		[http::]un	User name
-#		[http::]ul	User name from authentication
-#		[http::]ui	User name from ident
-#		[http::]us	User name from SSL
-#		[http::]ue	User name from external acl helper
-#		[http::]>Hs	HTTP status code sent to the client
-#		[http::]<Hs	HTTP status code received from the next hop
-#		[http::]Ss	Squid request status (TCP_MISS etc)
-#		[http::]Sh	Squid hierarchy status (DEFAULT_PARENT etc)
+#
 #		[http::]mt	MIME content type
-#		[http::]rm	Request method (GET/POST etc)
-#		[http::]ru	Request URL
-#		[http::]rp	Request URL-Path excluding hostname
-#		[http::]rv	Request protocol version
-#		[http::]et	Tag returned by external acl
-#		[http::]ea	Log string returned by external acl
-#		[http::]<st	Sent reply size including HTTP headers
-#		[http::]>st	Received request size including HTTP headers. In the
-#				case of chunked requests the chunked encoding metadata
-#				are not included
-#		[http::]>sh	Received HTTP request headers size
-#		[http::]<sh	Sent HTTP reply headers size
-#		[http::]st	Request+Reply size including HTTP headers
+#
+#
+#	    SIZE COUNTERS
+#
+#		[http::]st	Total size of request + reply traffic with client
+#		[http::]>st	Total size of request received from client.
+#				Excluding chunked encoding bytes.
+#		[http::]<st	Total size of reply sent to client (after adaptation)
+#
+#		[http::]>sh	Size of request headers received from client
+#		[http::]<sh	Size of reply headers sent to client (after adaptation)
+#
 #		[http::]<sH	Reply high offset sent
 #		[http::]<sS	Upstream object size
+#
+#		[http::]<bs	Number of HTTP-equivalent message body bytes 
+#				received from the next hop, excluding chunked
+#				transfer encoding and control messages.
+#				Generated FTP/Gopher listings are treated as
+#				received bodies.
+#
+#
+#	    TIMING
+#
 #		[http::]<pt	Peer response time in milliseconds. The timer starts
 #				when the last request byte is sent to the next hop
 #				and stops when the last response byte is received.
-#		[http::]<tt	Total server-side time in milliseconds. The timer 
+#		[http::]<tt	Total time in milliseconds. The timer 
 #				starts with the first connect request (or write I/O)
 #				sent to the first selected peer. The timer stops
 #				with the last I/O with the last peer.
 #
-#	If ICAP is enabled, the following two codes become available (as
+#	Squid handling related format codes:
+#
+#		Ss	Squid request status (TCP_MISS etc)
+#		Sh	Squid hierarchy status (DEFAULT_PARENT etc)
+#
+#	SSL-related format codes:
+#
+#		ssl::bump_mode	SslBump decision for the transaction:
+#
+#				For CONNECT requests that initiated bumping of
+#				a connection and for any request received on
+#				an already bumped connection, Squid logs the
+#				corresponding SslBump mode ("server-first" or
+#				"client-first"). See the ssl_bump option for
+#				more information about these modes.
+#
+#				A "none" token is logged for requests that
+#				triggered "ssl_bump" ACL evaluation matching
+#				either a "none" rule or no rules at all.
+#
+#				In all other cases, a single dash ("-") is
+#				logged.
+#
+#		ssl::>sni	SSL client SNI sent to Squid. Available only
+#				after the peek, stare, or splice SSL bumping
+#				actions.
+#
+#	If ICAP is enabled, the following code becomes available (as
 #	well as ICAP log codes documented with the icap_log option):
 #
 #		icap::tt        Total ICAP processing time for the HTTP
@@ -2386,14 +3793,13 @@ maximum_object_size 153600 KB
 #				ACLs are checked and when ICAP
 #				transaction is in progress.
 #
-#		icap::<last_h	The header of the last ICAP response
-#				related to the HTTP transaction. Like
-#				<h, accepts an optional header name
-#				argument.  Will not change semantics
-#				when multiple ICAP transactions per HTTP
-#				transaction are supported.
+#	If adaptation is enabled the following three codes become available:
 #
-#	If adaptation is enabled the following two codes become available:
+#		adapt::<last_h	The header of the last ICAP response or
+#				meta-information from the last eCAP
+#				transaction related to the HTTP transaction.
+#				Like <h, accepts an optional header name
+#				argument.
 #
 #		adapt::sum_trs Summed adaptation transaction response
 #				times recorded as a comma-separated list in
@@ -2417,43 +3823,118 @@ maximum_object_size 153600 KB
 #	service name in curly braces to record response time(s) specific
 #	to that service. For example: %{my_service}adapt::sum_trs
 #
+#	If SSL is enabled, the following formating codes become available:
+#
+#		%ssl::>cert_subject The Subject field of the received client
+#				SSL certificate or a dash ('-') if Squid has
+#				received an invalid/malformed certificate or
+#				no certificate at all. Consider encoding the
+#				logged value because Subject often has spaces.
+#
+#		%ssl::>cert_issuer The Issuer field of the received client
+#				SSL certificate or a dash ('-') if Squid has
+#				received an invalid/malformed certificate or
+#				no certificate at all. Consider encoding the
+#				logged value because Issuer often has spaces.
+#
 #	The default formats available (which do not need re-defining) are:
 #
-#logformat squid %ts.%03tu %6tr %>a %Ss/%03>Hs %<st %rm %ru %un %Sh/%<A %mt
-#logformat squidmime %ts.%03tu %6tr %>a %Ss/%03>Hs %<st %rm %ru %un %Sh/%<A %mt [%>h] [%<h]
-#logformat common %>a %ui %un [%tl] "%rm %ru HTTP/%rv" %>Hs %<st %Ss:%Sh
-#logformat combined %>a %ui %un [%tl] "%rm %ru HTTP/%rv" %>Hs %<st "%{Referer}>h" "%{User-Agent}>h" %Ss:%Sh
+#logformat squid      %ts.%03tu %6tr %>a %Ss/%03>Hs %<st %rm %ru %[un %Sh/%<a %mt
+#logformat common     %>a %[ui %[un [%tl] "%rm %ru HTTP/%rv" %>Hs %<st %Ss:%Sh
+#logformat combined   %>a %[ui %[un [%tl] "%rm %ru HTTP/%rv" %>Hs %<st "%{Referer}>h" "%{User-Agent}>h" %Ss:%Sh
+#logformat referrer   %ts.%03tu %>a %{Referer}>h %ru
+#logformat useragent  %>a [%tl] "%{User-Agent}>h"
+#
+#	NOTE: When the log_mime_hdrs directive is set to ON.
+#		The squid, common and combined formats have a safely encoded copy
+#		of the mime headers appended to each line within a pair of brackets.
+#
+#	NOTE: The common and combined formats are not quite true to the Apache definition.
+#		The logs from Squid contain an extra status and hierarchy code appended.
+#
 #Default:
-# none
+# The format definitions squid, common, combined, referrer, useragent are built in.
 
 #  TAG: access_log
-#	These files log client request activities. Has a line every HTTP or
-#	ICP request. The format is:
-#	access_log <filepath> [<logformat name> [acl acl ...]]
-#	access_log none [acl acl ...]]
+#	Configures whether and how Squid logs HTTP and ICP transactions.
+#	If access logging is enabled, a single line is logged for every 
+#	matching HTTP or ICP request. The recommended directive formats are:
 #
-#	Will log to the specified file using the specified format (which
-#	must be defined in a logformat directive) those entries which match
-#	ALL the acl's specified (which must be defined in acl clauses).
+#	access_log <module>:<place> [option ...] [acl acl ...]
+#	access_log none [acl acl ...]
 #
-#	If no acl is specified, all requests will be logged to this file.
+#	The following directive format is accepted but may be deprecated:
+#	access_log <module>:<place> [<logformat name> [acl acl ...]]
 #
-#	To disable logging of a request use the filepath "none", in which case
-#	a logformat name should not be specified.
+#        In most cases, the first ACL name must not contain the '=' character
+#	and should not be equal to an existing logformat name. You can always
+#	start with an 'all' ACL to work around those restrictions.
+#	
+#	Will log to the specified module:place using the specified format (which
+#	must be defined in a logformat directive) those entries which match
+#	ALL the acl's specified (which must be defined in acl clauses).
+#	If no acl is specified, all requests will be logged to this destination.
+#	
+#	===== Available options for the recommended directive format =====
+#
+#	logformat=name		Names log line format (either built-in or
+#				defined by a logformat directive). Defaults
+#				to 'squid'.
+#
+#	buffer-size=64KB	Defines approximate buffering limit for log
+#				records (see buffered_logs).  Squid should not
+#				keep more than the specified size and, hence,
+#				should flush records before the buffer becomes
+#				full to avoid overflows under normal
+#				conditions (the exact flushing algorithm is
+#				module-dependent though).  The on-error option
+#				controls overflow handling.
+#
+#	on-error=die|drop	Defines action on unrecoverable errors. The
+#				'drop' action ignores (i.e., does not log)
+#				affected log records. The default 'die' action
+#				kills the affected worker. The drop action 
+#				support has not been tested for modules other
+#				than tcp.
+#
+#	===== Modules Currently available =====
+#	
+#	none	Do not log any requests matching these ACL.
+#		Do not specify Place or logformat name.
+#	
+#	stdio	Write each log line to disk immediately at the completion of
+#		each request.
+#		Place: the filename and path to be written.
+#	
+#	daemon	Very similar to stdio. But instead of writing to disk the log
+#		line is passed to a daemon helper for asychronous handling instead.
+#		Place: varies depending on the daemon.
+#		
+#		log_file_daemon Place: the file name and path to be written.
+#	
+#	syslog	To log each request via syslog facility.
+#		Place: The syslog facility and priority level for these entries.
+#		Place Format:  facility.priority
 #
-#	To log the request via syslog specify a filepath of "syslog":
+#		where facility could be any of:
+#			authpriv, daemon, local0 ... local7 or user.
 #
-#	access_log syslog[:facility.priority] [format [acl1 [acl2 ....]]]
-#	where facility could be any of:
-#	authpriv, daemon, local0 .. local7 or user.
+#		And priority could be any of:
+#			err, warning, notice, info, debug.
+#	
+#	udp	To send each log line as text data to a UDP receiver.
+#		Place: The destination host name or IP and port.
+#		Place Format:   //host:port
 #
-#	And priority could be any of:
-#	err, warning, notice, info, debug.
+#	tcp	To send each log line as text data to a TCP receiver.
+#		Lines may be accumulated before sending (see buffered_logs).
+#		Place: The destination host name or IP and port.
+#		Place Format:   //host:port
 #
 #	Default:
-#		access_log /var/log/squid/access.log squid
+#		access_log daemon:/var/log/squid/access.log squid
 #Default:
-# access_log /var/log/squid/access.log squid
+# access_log daemon:/var/log/squid/access.log squid
 
 #  TAG: icap_log
 #	ICAP log files record ICAP transaction summaries, one line per
@@ -2472,13 +3953,35 @@ maximum_object_size 153600 KB
 #	ICAP transaction log lines will correspond to a single access
 #	log line.
 #
-#	ICAP log uses logformat codes that make sense for an ICAP
-#	transaction. Header-related codes are applied to the HTTP header
-#	embedded in an ICAP server response, with the following caveats:
-#	For REQMOD, there is no HTTP response header unless the ICAP
-#	server performed request satisfaction. For RESPMOD, the HTTP
-#	request header is the header sent to the ICAP server. For
-#	OPTIONS, there are no HTTP headers.
+#	ICAP log supports many access.log logformat %codes. In ICAP context,
+#	HTTP message-related %codes are applied to the HTTP message embedded
+#	in an ICAP message. Logformat "%http::>..." codes are used for HTTP
+#	messages embedded in ICAP requests while "%http::<..." codes are used
+#	for HTTP messages embedded in ICAP responses. For example:
+#
+#		http::>h	To-be-adapted HTTP message headers sent by Squid to
+#				the ICAP service. For REQMOD transactions, these are
+#				HTTP request headers. For RESPMOD, these are HTTP
+#				response headers, but Squid currently cannot log them
+#				(i.e., %http::>h will expand to "-" for RESPMOD).
+#
+#		http::<h	Adapted HTTP message headers sent by the ICAP
+#				service to Squid (i.e., HTTP request headers in regular
+#				REQMOD; HTTP response headers in RESPMOD and during
+#				request satisfaction in REQMOD).
+#
+#	ICAP OPTIONS transactions do not embed HTTP messages.
+#
+#	Several logformat codes below deal with ICAP message bodies. An ICAP
+#	message body, if any, typically includes a complete HTTP message
+#	(required HTTP headers plus optional HTTP message body). When
+#	computing HTTP message body size for these logformat codes, Squid
+#	either includes or excludes chunked encoding overheads; see
+#	code-specific documentation for details.
+#
+#	For Secure ICAP services, all size-related information is currently
+#	computed before/after TLS encryption/decryption, as if TLS was not
+#	in use at all.
 #
 #	The following format codes are also available for ICAP logs:
 #
@@ -2492,12 +3995,16 @@ maximum_object_size 153600 KB
 #		icap::rm	ICAP request method (REQMOD, RESPMOD, or 
 #				OPTIONS). Similar to existing rm.
 #
-#		icap::>st	Bytes sent to the ICAP server (TCP payload
-#				only; i.e., what Squid writes to the socket).
+#		icap::>st	The total size of the ICAP request sent to the ICAP
+#				server (ICAP headers + ICAP body), including chunking
+#				metadata (if any).
+#
+#		icap::<st	The total size of the ICAP response received from the
+#				ICAP server (ICAP headers + ICAP body), including
+#				chunking metadata (if any).
 #
-#		icap::<st	Bytes received from the ICAP server (TCP
-#				payload only; i.e., what Squid reads from
-#				the socket).
+#		icap::<bs	The size of the ICAP response body received from the
+#				ICAP server, excluding chunking metadata (if any).
 #
 #		icap::tr 	Transaction response time (in
 #				milliseconds).  The timer starts when
@@ -2527,37 +4034,51 @@ maximum_object_size 153600 KB
 #	The default ICAP log format, which can be used without an explicit
 #	definition, is called icap_squid:
 #
-#logformat icap_squid %ts.%03tu %6icap::tr %>a %icap::to/%03icap::Hs %icap::<size %icap::rm %icap::ru% %un -/%icap::<A -
+#logformat icap_squid %ts.%03tu %6icap::tr %>A %icap::to/%03icap::Hs %icap::<st %icap::rm %icap::ru %un -/%icap::<A -
 #
-#	See also: logformat, log_icap, and %icap::<last_h 
+#	See also: logformat and %adapt::<last_h
 #Default:
 # none
 
-#  TAG: log_access	allow|deny acl acl...
-#	This options allows you to control which requests gets logged
-#	to access.log (see access_log directive). Requests denied for
-#	logging will also not be accounted for in performance counters.
+#  TAG: logfile_daemon
+#	Specify the path to the logfile-writing daemon. This daemon is
+#	used to write the access and store logs, if configured.
 #
-#	This clause only supports fast acl types.
-#	See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
+#	Squid sends a number of commands to the log daemon:
+#	  L<data>\n - logfile data
+#	  R\n - rotate file
+#	  T\n - truncate file
+#	  O\n - reopen file
+#	  F\n - flush file
+#	  r<n>\n - set rotate count to <n>
+#	  b<n>\n - 1 = buffer output, 0 = don't buffer output
+#
+#	No responses is expected.
 #Default:
-# none
+# logfile_daemon /usr/lib/squid/log_file_daemon
 
-#  TAG: log_icap
-#	This options allows you to control which requests get logged
-#	to icap.log. See the icap_log directive for ICAP log details.
+#  TAG: stats_collection	allow|deny acl acl...
+#	This options allows you to control which requests gets accounted
+#	in performance counters.
+#
+#	This clause only supports fast acl types.
+#	See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
 #Default:
-# none
+# Allow logging for all transactions.
 
 #  TAG: cache_store_log
 #	Logs the activities of the storage manager.  Shows which
 #	objects are ejected from the cache, and which objects are
-#	saved and for how long.  To disable, enter "none" or remove the line.
+#	saved and for how long.
 #	There are not really utilities to analyze this data, so you can safely
-#	disable it.
-#
+#	disable it (the default).
+#	
+#	Store log uses modular logging outputs. See access_log for the list
+#	of modules supported.
+#	
 #	Example:
-#		cache_store_log /var/log/squid/store.log
+#		cache_store_log stdio:/var/log/squid/store.log
+#		cache_store_log daemon:/var/log/squid/store.log
 #Default:
 # none
 
@@ -2590,7 +4111,7 @@ maximum_object_size 153600 KB
 #	them).  We recommend you do NOT use this option.  It is
 #	better to keep these index files in each 'cache_dir' directory.
 #Default:
-# none
+# Store the journal inside its cache_dir
 
 #  TAG: logfile_rotate
 #	Specifies the number of logfile rotations to make when you
@@ -2607,34 +4128,19 @@ maximum_object_size 153600 KB
 #	in the habit of using 'squid -k rotate' instead of 'kill -USR1
 #	<pid>'.
 #
-#	Note, from Squid-3.1 this option has no effect on the cache.log,
-#	that log can be rotated separately by using debug_options
+#	Note, from Squid-3.1 this option is only a default for cache.log,
+#	that log can be rotated separately by using debug_options.
 #
-# 	Note2, for Debian/Linux the default of logfile_rotate is
-# 	zero, since it includes external logfile-rotation methods.
+#	Note2, for Debian/Linux the default of logfile_rotate is
+#	zero, since it includes external logfile-rotation methods.
 #Default:
 # logfile_rotate 0
 
-#  TAG: emulate_httpd_log	on|off
-#	The Cache can emulate the log file format which many 'httpd'
-#	programs use.  To disable/enable this emulation, set
-#	emulate_httpd_log to 'off' or 'on'.  The default
-#	is to use the native log format since it includes useful
-#	information Squid-specific log analyzers use.
-#Default:
-# emulate_httpd_log off
-
-#  TAG: log_ip_on_direct	on|off
-#	Log the destination IP address in the hierarchy log tag when going
-#	direct. Earlier Squid versions logged the hostname here. If you
-#	prefer the old way set this to off.
-#Default:
-# log_ip_on_direct on
-
 #  TAG: mime_table
-#	Pathname to Squid's MIME table. You shouldn't need to change
-#	this, but the default file contains examples and formatting
-#	information if you do.
+#	Path to Squid's icon configuration file.
+#
+#	You shouldn't need to change this, but the default file contains
+#	examples and formatting information if you do.
 #Default:
 # mime_table /usr/share/squid/mime.conf
 
@@ -2647,91 +4153,61 @@ maximum_object_size 153600 KB
 #Default:
 # log_mime_hdrs off
 
-#  TAG: useragent_log
-# Note: This option is only available if Squid is rebuilt with the
-#       --enable-useragent-log option
-#
-#	Squid will write the User-Agent field from HTTP requests
-#	to the filename specified here.  By default useragent_log
-#	is disabled.
-#Default:
-# none
-
-#  TAG: referer_log
-# Note: This option is only available if Squid is rebuilt with the
-#       --enable-referer-log option
-#
-#	Squid will write the Referer field from HTTP requests to the
-#	filename specified here.  By default referer_log is disabled.
-#	Note that "referer" is actually a misspelling of "referrer"
-#	however the misspelt version has been accepted into the HTTP RFCs
-#	and we accept both.
-#Default:
-# none
-
 #  TAG: pid_filename
 #	A filename to write the process-id to.  To disable, enter "none".
 #Default:
 # pid_filename /var/run/squid.pid
 
-#  TAG: log_fqdn	on|off
-#	Turn this on if you wish to log fully qualified domain names
-#	in the access.log. To do this Squid does a DNS lookup of all
-#	IP's connecting to it. This can (in some situations) increase
-#	latency, which makes your cache seem slower for interactive
-#	browsing.
-#Default:
-# log_fqdn off
-
 #  TAG: client_netmask
 #	A netmask for client addresses in logfiles and cachemgr output.
 #	Change this to protect the privacy of your cache clients.
 #	A netmask of 255.255.255.0 will log all IP's in that range with
 #	the last digit set to '0'.
 #Default:
-# client_netmask no_addr
-
-#  TAG: forward_log
-# Note: This option is only available if Squid is rebuilt with the
-#       -DWIP_FWD_LOG define
-#
-#	Logs the server-side requests.
-#
-#	This is currently work in progress.
-#Default:
-# none
+# Log full client IP address
 
 #  TAG: strip_query_terms
 #	By default, Squid strips query terms from requested URLs before
-#	logging.  This protects your user's privacy.
+#	logging.  This protects your user's privacy and reduces log size.
+#
+#	When investigating HIT/MISS or other caching behaviour you
+#	will need to disable this to see the full URL used by Squid.
 #Default:
 # strip_query_terms on
 
 #  TAG: buffered_logs	on|off
-#	cache.log log file is written with stdio functions, and as such
-#	it can be buffered or unbuffered. By default it will be unbuffered.
-#	Buffering it can speed up the writing slightly (though you are
-#	unlikely to need to worry unless you run with tons of debugging
-#	enabled in which case performance will suffer badly anyway..).
+#	Whether to write/send access_log records ASAP or accumulate them and
+#	then write/send them in larger chunks. Buffering may improve
+#	performance because it decreases the number of I/Os. However,
+#	buffering increases the delay before log records become available to
+#	the final recipient (e.g., a disk file or logging daemon) and,
+#	hence, increases the risk of log records loss.
+#
+#	Note that even when buffered_logs are off, Squid may have to buffer
+#	records if it cannot write/send them immediately due to pending I/Os
+#	(e.g., the I/O writing the previous log record) or connectivity loss.
+#
+#	Currently honored by 'daemon' and 'tcp' access_log modules only.
 #Default:
 # buffered_logs off
 
 #  TAG: netdb_filename
-# Note: This option is only available if Squid is rebuilt with the
-#       --enable-icmp option
+#	Where Squid stores it's netdb journal.
+#	When enabled this journal preserves netdb state between restarts.
 #
-#	A filename where Squid stores it's netdb state between restarts.
 #	To disable, enter "none".
 #Default:
-# netdb_filename /var/log/squid/netdb.state
+# netdb_filename stdio:/var/log/squid/netdb.state
 
 # OPTIONS FOR TROUBLESHOOTING
 # -----------------------------------------------------------------------------
 
 #  TAG: cache_log
-#	Cache logging file. This is where general information about
-#	your cache's behavior goes. You can increase the amount of data
-#	logged to this file and how often its rotated with "debug_options"
+#	Squid administrative logging file.
+#
+#	This is where general information about Squid behavior goes. You can
+#	increase the amount of data logged to this file and how often it is
+#	rotated with "debug_options"
 #Default:
 # cache_log /var/log/squid/cache.log
 
@@ -2742,14 +4218,14 @@ maximum_object_size 153600 KB
 #	log file, so be careful.
 #
 #	The magic word "ALL" sets debugging levels for all sections.
-#	We recommend normally running with "ALL,1".
+#	The default is to run with "ALL,1" to record important warnings.
 #
 #	The rotate=N option can be used to keep more or less of these logs
 #	than would otherwise be kept by logfile_rotate.
 #	For most uses a single log should be enough to monitor current
 #	events affecting Squid.
 #Default:
-# debug_options ALL,1
+# Log all critical and important messages.
 
 #  TAG: coredump_dir
 #	By default Squid leaves core files in the directory from where
@@ -2758,7 +4234,7 @@ maximum_object_size 153600 KB
 #	and coredump files will be left there.
 #
 #Default:
-# coredump_dir none
+# Use the directory from where Squid was started.
 #
 
 # Leave coredumps in the first cache dir
@@ -2769,24 +4245,17 @@ coredump_dir /var/spool/squid
 
 #  TAG: ftp_user
 #	If you want the anonymous login password to be more informative
-#	(and enable the use of picky ftp servers), set this to something
+#	(and enable the use of picky FTP servers), set this to something
 #	reasonable for your domain, like wwwuser@somewhere.net
 #
 #	The reason why this is domainless by default is the
 #	request can be made on the behalf of a user in any domain,
 #	depending on how the cache is used.
-#	Some ftp server also validate the email address is valid
+#	Some FTP server also validate the email address is valid
 #	(for example perl.com).
 #Default:
 # ftp_user Squid@
 
-#  TAG: ftp_list_width
-#	Sets the width of ftp listings. This should be set to fit in
-#	the width of a standard browser. Setting this too small
-#	can cut off long filenames when browsing ftp sites.
-#Default:
-# ftp_list_width 32
-
 #  TAG: ftp_passive
 #	If your firewall does not allow Squid to use passive
 #	connections, turn off this option.
@@ -2822,13 +4291,21 @@ coredump_dir /var/spool/squid
 #	and therefore, translation of the data portion of the segments 
 #	will never be needed.
 #
-#	Turning this OFF will prevent EPSV being attempted.
-#	WARNING: Doing so will convert Squid back to the old behavior with all
-#	the related problems with external NAT devices/layers.
+#	EPSV is often required to interoperate with FTP servers on IPv6
+#	networks. On the other hand, it may break some IPv4 servers.
+#
+#	By default, EPSV may try EPSV with any FTP server. To fine tune
+#	that decision, you may restrict EPSV to certain clients or servers
+#	using ACLs:
 #
+#		ftp_epsv allow|deny al1 acl2 ...
+#
+#	WARNING: Disabling EPSV may cause problems with external NAT and IPv6.
+#
+#	Only fast ACLs are supported.
 #	Requires ftp_passive to be ON (default) for any effect.
 #Default:
-# ftp_epsv on
+# none
 
 #  TAG: ftp_eprt
 #	FTP Protocol extensions permit the use of a special "EPRT" command.
@@ -2889,22 +4366,16 @@ coredump_dir /var/spool/squid
 # unlinkd_program /usr/lib/squid/unlinkd
 
 #  TAG: pinger_program
-# Note: This option is only available if Squid is rebuilt with the
-#       --enable-icmp option
-#
 #	Specify the location of the executable for the pinger process.
 #Default:
 # pinger_program /usr/lib/squid/pinger
 
 #  TAG: pinger_enable
-# Note: This option is only available if Squid is rebuilt with the
-#       --enable-icmp option
-#
 #	Control whether the pinger is active at run-time.
 #	Enables turning ICMP pinger on and off with a simple
 #	squid -k reconfigure.
 #Default:
-# pinger_enable off
+# pinger_enable on
 
 # OPTIONS FOR URL REWRITING
 # -----------------------------------------------------------------------------
@@ -2915,68 +4386,137 @@ coredump_dir /var/spool/squid
 #
 #	For each requested URL, the rewriter will receive on line with the format
 #
-#	URL <SP> client_ip "/" fqdn <SP> user <SP> method [<SP> kvpairs]<NL>
+#	  [channel-ID <SP>] URL [<SP> extras]<NL>
+#
+#	See url_rewrite_extras on how to send "extras" with optional values to
+#	the helper.
+#	After processing the request the helper must reply using the following format:
+#
+#	  [channel-ID <SP>] result [<SP> kv-pairs]
+#
+#	The result code can be:
 #
-#	In the future, the rewriter interface will be extended with
-#	key=value pairs ("kvpairs" shown above).  Rewriter programs
-#	should be prepared to receive and possibly ignore additional
-#	whitespace-separated tokens on each input line.
+#	  OK status=30N url="..."
+#		Redirect the URL to the one supplied in 'url='.
+#		'status=' is optional and contains the status code to send
+#		the client in Squids HTTP response. It must be one of the
+#		HTTP redirect status codes: 301, 302, 303, 307, 308.
+#		When no status is given Squid will use 302.
+#
+#	  OK rewrite-url="..."
+#		Rewrite the URL to the one supplied in 'rewrite-url='.
+#		The new URL is fetched directly by Squid and returned to
+#		the client as the response to its request.
+#
+#	  OK
+#		When neither of url= and rewrite-url= are sent Squid does
+#		not change the URL.
+#
+#	  ERR
+#		Do not change the URL.
+#
+#	  BH
+#		An internal error occurred in the helper, preventing
+#		a result being identified. The 'message=' key name is
+#		reserved for delivering a log message.
+#
+#
+#	In addition to the above kv-pairs Squid also understands the following
+#	optional kv-pairs received from URL rewriters:
+#	  clt_conn_tag=TAG
+#		Associates a TAG with the client TCP connection.
+#		The TAG is treated as a regular annotation but persists across
+#		future requests on the client connection rather than just the
+#		current request. A helper may update the TAG during subsequent
+#		requests be returning a new kv-pair.
+#
+#	When using the concurrency= option the protocol is changed by
+#	introducing a query channel tag in front of the request/response.
+#	The query channel tag is a number between 0 and concurrency-1.
+#	This value must be echoed back unchanged to Squid as the first part
+#	of the response relating to its request.
 #
-#	And the rewriter may return a rewritten URL. The other components of
-#	the request line does not need to be returned (ignored if they are).
+#	WARNING: URL re-writing ability should be avoided whenever possible.
+#		 Use the URL redirect form of response instead.
 #
-#	The rewriter can also indicate that a client-side redirect should
-#	be performed to the new URL. This is done by prefixing the returned
-#	URL with "301:" (moved permanently) or 302: (moved temporarily), etc.
+#	Re-write creates a difference in the state held by the client
+#	and server. Possibly causing confusion when the server response
+#	contains snippets of its view state. Embeded URLs, response
+#	and content Location headers, etc. are not re-written by this
+#	interface.
 #
 #	By default, a URL rewriter is not used.
 #Default:
 # none
 
 #  TAG: url_rewrite_children
-#	The number of redirector processes to spawn. If you start
-#	too few Squid will have to wait for them to process a backlog of
-#	URLs, slowing it down. If you start too many they will use RAM
-#	and other system resources.
-#Default:
-# url_rewrite_children 5
-
-#  TAG: url_rewrite_concurrency
+#	The maximum number of redirector processes to spawn. If you limit
+#	it too few Squid will have to wait for them to process a backlog of
+#	URLs, slowing it down. If you allow too many they will use RAM
+#	and other system resources noticably.
+#	
+#	The startup= and idle= options allow some measure of skew in your
+#	tuning.
+#	
+#		startup=
+#	
+#	Sets a minimum of how many processes are to be spawned when Squid
+#	starts or reconfigures. When set to zero the first request will
+#	cause spawning of the first child process to handle it.
+#	
+#	Starting too few will cause an initial slowdown in traffic as Squid
+#	attempts to simultaneously spawn enough processes to cope.
+#	
+#		idle=
+#	
+#	Sets a minimum of how many processes Squid is to try and keep available
+#	at all times. When traffic begins to rise above what the existing
+#	processes can handle this many more will be spawned up to the maximum
+#	configured. A minimum setting of 1 is required.
+#
+#		concurrency=
+#
 #	The number of requests each redirector helper can handle in
 #	parallel. Defaults to 0 which indicates the redirector
 #	is a old-style single threaded redirector.
 #
 #	When this directive is set to a value >= 1 then the protocol
 #	used to communicate with the helper is modified to include
-#	a request ID in front of the request/response. The request
-#	ID from the request must be echoed back with the response
-#	to that request.
+#	an ID in front of the request/response. The ID from the request
+#	must be echoed back with the response to that request.
 #Default:
-# url_rewrite_concurrency 0
+# url_rewrite_children 20 startup=0 idle=1 concurrency=0
 
 #  TAG: url_rewrite_host_header
-#	By default Squid rewrites any Host: header in redirected
-#	requests.  If you are running an accelerator this may
-#	not be a wanted effect of a redirector.
-#
+#	To preserve same-origin security policies in browsers and
+#	prevent Host: header forgery by redirectors Squid rewrites
+#	any Host: header in redirected requests.
+#	
+#	If you are running an accelerator this may not be a wanted
+#	effect of a redirector. This directive enables you disable
+#	Host: alteration in reverse-proxy traffic.
+#	
 #	WARNING: Entries are cached on the result of the URL rewriting
 #	process, so be careful if you have domain-virtual hosts.
+#	
+#	WARNING: Squid and other software verifies the URL and Host
+#	are matching, so be careful not to relay through other proxies
+#	or inspecting firewalls with this disabled.
 #Default:
 # url_rewrite_host_header on
 
 #  TAG: url_rewrite_access
 #	If defined, this access list specifies which requests are
-#	sent to the redirector processes.  By default all requests
-#	are sent.
+#	sent to the redirector processes.
 #
 #	This clause supports both fast and slow acl types.
 #	See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
 #Default:
-# none
+# Allow, unless rules exist in squid.conf.
 
 #  TAG: url_rewrite_bypass
 #	When this is 'on', a request will not go through the
-#	redirector if all redirectors are busy.  If this is 'off'
+#	redirector if all the helpers are busy.  If this is 'off'
 #	and the redirector queue grows too large, Squid will exit
 #	with a FATAL error and ask you to increase the number of
 #	redirectors.  You should only enable this if the redirectors
@@ -2987,23 +4527,231 @@ coredump_dir /var/spool/squid
 #Default:
 # url_rewrite_bypass off
 
-# OPTIONS FOR TUNING THE CACHE
+#  TAG: url_rewrite_extras
+#	Specifies a string to be append to request line format for the
+#	rewriter helper. "Quoted" format values may contain spaces and
+#	logformat %macros. In theory, any logformat %macro can be used.
+#	In practice, a %macro expands as a dash (-) if the helper request is
+#	sent before the required macro information is available to Squid.
+#Default:
+# url_rewrite_extras "%>a/%>A %un %>rm myip=%la myport=%lp"
+
+# OPTIONS FOR STORE ID
 # -----------------------------------------------------------------------------
 
-#  TAG: cache
-#	A list of ACL elements which, if matched and denied, cause the request to
-#	not be satisfied from the cache and the reply to not be cached.
-#	In other words, use this to force certain objects to never be cached.
+#  TAG: store_id_program
+#	Specify the location of the executable StoreID helper to use.
+#	Since they can perform almost any function there isn't one included.
+#
+#	For each requested URL, the helper will receive one line with the format
+#
+#	  [channel-ID <SP>] URL [<SP> extras]<NL>
+#
+#
+#	After processing the request the helper must reply using the following format:
+#
+#	  [channel-ID <SP>] result [<SP> kv-pairs]
+#
+#	The result code can be:
+#
+#	  OK store-id="..."
+#		Use the StoreID supplied in 'store-id='.
+#
+#	  ERR
+#		The default is to use HTTP request URL as the store ID.
+#
+#	  BH
+#		An internal error occured in the helper, preventing
+#		a result being identified.
+#
+#	In addition to the above kv-pairs Squid also understands the following
+#	optional kv-pairs received from URL rewriters:
+#	  clt_conn_tag=TAG
+#		Associates a TAG with the client TCP connection.
+#		Please see url_rewrite_program related documentation for this
+#		kv-pair
+#
+#	Helper programs should be prepared to receive and possibly ignore
+#	additional whitespace-separated tokens on each input line.
 #
-#	You must use the words 'allow' or 'deny' to indicate whether items
-#	matching the ACL should be allowed or denied into the cache.
+#	When using the concurrency= option the protocol is changed by
+#	introducing a query channel tag in front of the request/response.
+#	The query channel tag is a number between 0 and concurrency-1.
+#	This value must be echoed back unchanged to Squid as the first part
+#	of the response relating to its request.
+#
+#	NOTE: when using StoreID refresh_pattern will apply to the StoreID
+#	      returned from the helper and not the URL.
+#
+#	WARNING: Wrong StoreID value returned by a careless helper may result
+#	         in the wrong cached response returned to the user.
+#
+#	By default, a StoreID helper is not used.
+#Default:
+# none
+
+#  TAG: store_id_extras
+#        Specifies a string to be append to request line format for the
+#        StoreId helper. "Quoted" format values may contain spaces and
+#        logformat %macros. In theory, any logformat %macro can be used.
+#        In practice, a %macro expands as a dash (-) if the helper request is
+#        sent before the required macro information is available to Squid.
+#Default:
+# store_id_extras "%>a/%>A %un %>rm myip=%la myport=%lp"
+
+#  TAG: store_id_children
+#	The maximum number of StoreID helper processes to spawn. If you limit
+#	it too few Squid will have to wait for them to process a backlog of
+#	requests, slowing it down. If you allow too many they will use RAM
+#	and other system resources noticably.
+#	
+#	The startup= and idle= options allow some measure of skew in your
+#	tuning.
+#	
+#		startup=
+#	
+#	Sets a minimum of how many processes are to be spawned when Squid
+#	starts or reconfigures. When set to zero the first request will
+#	cause spawning of the first child process to handle it.
+#	
+#	Starting too few will cause an initial slowdown in traffic as Squid
+#	attempts to simultaneously spawn enough processes to cope.
+#	
+#		idle=
+#	
+#	Sets a minimum of how many processes Squid is to try and keep available
+#	at all times. When traffic begins to rise above what the existing
+#	processes can handle this many more will be spawned up to the maximum
+#	configured. A minimum setting of 1 is required.
 #
-#	Default is to allow all to be cached.
+#		concurrency=
+#
+#	The number of requests each storeID helper can handle in
+#	parallel. Defaults to 0 which indicates the helper
+#	is a old-style single threaded program.
+#
+#	When this directive is set to a value >= 1 then the protocol
+#	used to communicate with the helper is modified to include
+#	an ID in front of the request/response. The ID from the request
+#	must be echoed back with the response to that request.
+#Default:
+# store_id_children 20 startup=0 idle=1 concurrency=0
+
+#  TAG: store_id_access
+#	If defined, this access list specifies which requests are
+#	sent to the StoreID processes.  By default all requests
+#	are sent.
 #
 #	This clause supports both fast and slow acl types.
 #	See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
 #Default:
-# none
+# Allow, unless rules exist in squid.conf.
+
+#  TAG: store_id_bypass
+#	When this is 'on', a request will not go through the
+#	helper if all helpers are busy.  If this is 'off'
+#	and the helper queue grows too large, Squid will exit
+#	with a FATAL error and ask you to increase the number of
+#	helpers.  You should only enable this if the helperss
+#	are not critical to your caching system.  If you use
+#	helpers for critical caching components, and you enable this 
+#	option,	users may not get objects from cache.
+#Default:
+# store_id_bypass on
+
+# OPTIONS FOR TUNING THE CACHE
+# -----------------------------------------------------------------------------
+
+#  TAG: cache
+#	Requests denied by this directive will not be served from the cache
+#	and their responses will not be stored in the cache. This directive
+#	has no effect on other transactions and on already cached responses.
+#
+#	This clause supports both fast and slow acl types.
+#	See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
+#
+#	This and the two other similar caching directives listed below are
+#	checked at different transaction processing stages, have different
+#	access to response information, affect different cache operations,
+#	and differ in slow ACLs support:
+#
+#	* cache: Checked before Squid makes a hit/miss determination.
+#		No access to reply information!
+#		Denies both serving a hit and storing a miss.
+#		Supports both fast and slow ACLs.
+#	* send_hit: Checked after a hit was detected.
+#		Has access to reply (hit) information.
+#		Denies serving a hit only.
+#		Supports fast ACLs only.
+#	* store_miss: Checked before storing a cachable miss.
+#		Has access to reply (miss) information.
+#		Denies storing a miss only.
+#		Supports fast ACLs only.
+#
+#	If you are not sure which of the three directives to use, apply the
+#	following decision logic:
+#
+#	* If your ACL(s) are of slow type _and_ need response info, redesign.
+#	  Squid does not support that particular combination at this time.
+#        Otherwise:
+#	* If your directive ACL(s) are of slow type, use "cache"; and/or
+#	* if your directive ACL(s) need no response info, use "cache".
+#        Otherwise:
+#	* If you do not want the response cached, use store_miss; and/or
+#	* if you do not want a hit on a cached response, use send_hit.
+#Default:
+# By default, this directive is unused and has no effect.
+
+#  TAG: send_hit
+#	Responses denied by this directive will not be served from the cache
+#	(but may still be cached, see store_miss). This directive has no
+#	effect on the responses it allows and on the cached objects.
+#
+#	Please see the "cache" directive for a summary of differences among
+#	store_miss, send_hit, and cache directives.
+#
+#	Unlike the "cache" directive, send_hit only supports fast acl
+#	types.  See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
+#
+#	For example:
+#
+#		# apply custom Store ID mapping to some URLs
+#		acl MapMe dstdomain .c.example.com
+#		store_id_program ...
+#		store_id_access allow MapMe
+#
+#		# but prevent caching of special responses
+#		# such as 302 redirects that cause StoreID loops
+#		acl Ordinary http_status 200-299
+#		store_miss deny MapMe !Ordinary
+#
+#		# and do not serve any previously stored special responses
+#		# from the cache (in case they were already cached before
+#		# the above store_miss rule was in effect).
+#		send_hit deny MapMe !Ordinary
+#Default:
+# By default, this directive is unused and has no effect.
+
+#  TAG: store_miss
+#	Responses denied by this directive will not be cached (but may still
+#	be served from the cache, see send_hit). This directive has no
+#	effect on the responses it allows and on the already cached responses.
+#
+#	Please see the "cache" directive for a summary of differences among
+#	store_miss, send_hit, and cache directives. See the
+#	send_hit directive for a usage example.
+#
+#	Unlike the "cache" directive, store_miss only supports fast acl
+#	types.  See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
+#Default:
+# By default, this directive is unused and has no effect.
+
+#  TAG: max_stale	time-units
+#	This option puts an upper limit on how stale content Squid
+#	will serve from the cache if cache validation fails.
+#	Can be overriden by the refresh_pattern max-stale option.
+#Default:
+# max_stale 1 week
 
 #  TAG: refresh_pattern
 #	usage: refresh_pattern [-i] regex min percent max [options]
@@ -3028,12 +4776,13 @@ coredump_dir /var/spool/squid
 #		 override-lastmod
 #		 reload-into-ims
 #		 ignore-reload
-#		 ignore-no-cache
 #		 ignore-no-store
 #		 ignore-must-revalidate
 #		 ignore-private
 #		 ignore-auth
+#		 max-stale=NN
 #		 refresh-ims
+#		 store-stale
 #
 #		override-expire enforces min age even if the server
 #		sent an explicit expiry time (e.g., with the
@@ -3049,22 +4798,18 @@ coredump_dir /var/spool/squid
 #		override-lastmod enforces min age even on objects
 #		that were modified recently.
 #
-#		reload-into-ims changes client no-cache or ``reload''
-#		to If-Modified-Since requests. Doing this VIOLATES the
-#		HTTP standard. Enabling this feature could make you
-#		liable for problems which it causes.
+#		reload-into-ims changes a client no-cache or ``reload''
+#		request for a cached entry into a conditional request using
+#		If-Modified-Since and/or If-None-Match headers, provided the
+#		cached entry has a Last-Modified and/or a strong ETag header.
+#		Doing this VIOLATES the HTTP standard. Enabling this feature
+#		could make you liable for problems which it causes.
 #
 #		ignore-reload ignores a client no-cache or ``reload''
 #		header. Doing this VIOLATES the HTTP standard. Enabling
 #		this feature could make you liable for problems which
 #		it causes.
 #
-#		ignore-no-cache ignores any ``Pragma: no-cache'' and
-#		``Cache-control: no-cache'' headers received from a server.
-#		The HTTP RFC never allows the use of this (Pragma) header
-#		from a server, only a client, though plenty of servers
-#		send it anyway.
-#
 #		ignore-no-store ignores any ``Cache-control: no-store''
 #		headers received from a server. Doing this VIOLATES
 #		the HTTP standard. Enabling this feature could make you
@@ -3091,9 +4836,19 @@ coredump_dir /var/spool/squid
 #		ensures that the client will receive an updated version
 #		if one is available.
 #
+#		store-stale stores responses even if they don't have explicit 
+#		freshness or a validator (i.e., Last-Modified or an ETag) 
+#		present, or if they're already stale. By default, Squid will 
+#		not cache such responses because they usually can't be
+#		reused. Note that such responses will be stale by default.
+#
+#		max-stale=NN provide a maximum staleness factor. Squid won't
+#		serve objects more stale than this even if it failed to
+#		validate the object. Default: use the max_stale global limit.
+#
 #	Basically a cached object is:
 #
-#		FRESH if expires < now, else STALE
+#		FRESH if expire > now, else STALE
 #		STALE if age > max
 #		FRESH if lm-factor < percent, else STALE
 #		FRESH if age < min
@@ -3109,7 +4864,9 @@ coredump_dir /var/spool/squid
 #
 #
 
+#
 # Add any of your own refresh_pattern entries above these.
+#
 refresh_pattern ^ftp:		1440	20%	10080
 refresh_pattern ^gopher:	1440	0%	1440
 refresh_pattern -i (/cgi-bin/|\?) 0	0%	0
@@ -3137,7 +4894,7 @@ refresh_pattern .		0	20%	4320
 #	downloads.
 #
 #	When the user aborts a request, Squid will check the
-#	quick_abort values to the amount of data transfered until
+#	quick_abort values to the amount of data transferred until
 #	then.
 #
 #	If the transfer has less than 'quick_abort_min' KB remaining,
@@ -3195,44 +4952,68 @@ refresh_pattern .		0	20%	4320
 #Default:
 # negative_dns_ttl 1 minutes
 
-#  TAG: range_offset_limit	(bytes)
-#	Sets a upper limit on how far into the the file a Range request
-#	may be to cause Squid to prefetch the whole file. If beyond this
-#	limit Squid forwards the Range request as it is and the result
-#	is NOT cached.
-#
+#  TAG: range_offset_limit	size [acl acl...]
+#	usage: (size) [units] [[!]aclname]
+#	
+#	Sets an upper limit on how far (number of bytes) into the file 
+#	a Range request	may be to cause Squid to prefetch the whole file. 
+#	If beyond this limit, Squid forwards the Range request as it is and 
+#	the result is NOT cached.
+#	
 #	This is to stop a far ahead range request (lets say start at 17MB)
 #	from making Squid fetch the whole object up to that point before
 #	sending anything to the client.
-#
-#	A value of 0 causes Squid to never fetch more than the
+#	
+#	Multiple range_offset_limit lines may be specified, and they will 
+#	be searched from top to bottom on each request until a match is found. 
+#	The first match found will be used.  If no line matches a request, the 
+#	default limit of 0 bytes will be used.
+#	
+#	'size' is the limit specified as a number of units.
+#	
+#	'units' specifies whether to use bytes, KB, MB, etc.
+#	If no units are specified bytes are assumed.
+#	
+#	A size of 0 causes Squid to never fetch more than the
 #	client requested. (default)
-#
-#	A value of -1 causes Squid to always fetch the object from the
+#	
+#	A size of 'none' causes Squid to always fetch the object from the
 #	beginning so it may cache the result. (2.0 style)
-#
-#	NP: Using -1 here will override any quick_abort settings that may
-#	    otherwise apply to the range request. The range request will
+#	
+#	'aclname' is the name of a defined ACL.
+#	
+#	NP: Using 'none' as the byte value here will override any quick_abort settings 
+#	    that may otherwise apply to the range request. The range request will
 #	    be fully fetched from start to finish regardless of the client
 #	    actions. This affects bandwidth usage.
 #Default:
-# range_offset_limit 0 KB
+# none
 
 #  TAG: minimum_expiry_time	(seconds)
 #	The minimum caching time according to (Expires - Date)
-#	Headers Squid honors if the object can't be revalidated
-#	defaults to 60 seconds. In reverse proxy environments it
-#	might be desirable to honor shorter object lifetimes. It
-#	is most likely better to make your server return a
-#	meaningful Last-Modified header however. In ESI environments
-#	where page fragments often have short lifetimes, this will
-#	often be best set to 0.
+#	headers Squid honors if the object can't be revalidated.
+#	The default is 60 seconds.
+#
+#	In reverse proxy environments it might be desirable to honor
+#	shorter object lifetimes. It is most likely better to make
+#	your server return a meaningful Last-Modified header however.
+#
+#	In ESI environments where page fragments often have short
+#	lifetimes, this will often be best set to 0.
 #Default:
 # minimum_expiry_time 60 seconds
 
-#  TAG: store_avg_object_size	(kbytes)
+#  TAG: store_avg_object_size	(bytes)
 #	Average object size, used to estimate number of objects your
 #	cache can hold.  The default is 13 KB.
+#
+#	This is used to pre-seed the cache index memory allocation to
+#	reduce expensive reallocate operations while handling clients
+#	traffic. Too-large values may result in memory allocation during
+#	peak traffic, too-small values will result in wasted memory.
+#
+#	Check the cache manager 'info' report metrics for the real
+#	object sizes seen by your Squid before tuning this.
 #Default:
 # store_avg_object_size 13 KB
 
@@ -3271,8 +5052,11 @@ refresh_pattern .		0	20%	4320
 #	than this limit receives an "Invalid Request" error message.
 #	If you set this parameter to a zero (the default), there will
 #	be no limit imposed.
+#
+#	See also client_request_buffer_max_size for an alternative
+#	limitation on client uploads which can be configured.
 #Default:
-# request_body_max_size 0 KB
+# No limit.
 
 #  TAG: client_request_buffer_max_size	(bytes)
 #	This specifies the maximum buffer size of a client request.
@@ -3281,29 +5065,6 @@ refresh_pattern .		0	20%	4320
 #Default:
 # client_request_buffer_max_size 512 KB
 
-#  TAG: chunked_request_body_max_size	(bytes)
-#	A broken or confused HTTP/1.1 client may send a chunked HTTP
-#	request to Squid. Squid does not have full support for that
-#	feature yet. To cope with such requests, Squid buffers the
-#	entire request and then dechunks request body to create a
-#	plain HTTP/1.0 request with a known content length. The plain
-#	request is then used by the rest of Squid code as usual.
-#
-#	The option value specifies the maximum size of the buffer used
-#	to hold the request before the conversion. If the chunked
-#	request size exceeds the specified limit, the conversion
-#	fails, and the client receives an "unsupported request" error,
-#	as if dechunking was disabled.
-#
-#	Dechunking is enabled by default. To disable conversion of
-#	chunked requests, set the maximum to zero.
-#
-#	Request dechunking feature and this option in particular are a
-#	temporary hack. When chunking requests and responses are fully
-#	supported, there will be no need to buffer a chunked request.
-#Default:
-# chunked_request_body_max_size 64 KB
-
 #  TAG: broken_posts
 #	A list of ACL elements which, if matched, causes Squid to send
 #	an extra CRLF pair after the body of a PUT/POST request.
@@ -3325,15 +5086,15 @@ refresh_pattern .		0	20%	4320
 # acl buggy_server url_regex ^http://....
 # broken_posts allow buggy_server
 #Default:
-# none
+# Obey RFC 2616.
 
-#  TAG: icap_uses_indirect_client	on|off
+#  TAG: adaptation_uses_indirect_client	on|off
 #	Controls whether the indirect client IP address (instead of the direct
 #	client IP address) is passed to adaptation services.
 #
 #	See also: follow_x_forwarded_for adaptation_send_client_ip
 #Default:
-# icap_uses_indirect_client on
+# adaptation_uses_indirect_client on
 
 #  TAG: via	on|off
 #	If set (default), Squid will include a Via header in requests and
@@ -3395,64 +5156,62 @@ refresh_pattern .		0	20%	4320
 #
 #	This option replaces the old 'anonymize_headers' and the
 #	older 'http_anonymizer' option with something that is much
-#	more configurable. This new method creates a list of ACLs
-#	for each header, allowing you very fine-tuned header
-#	mangling.
-#
-#	This option only applies to request headers, i.e., from the
-#	client to the server.
-#
-#	You can only specify known headers for the header name.
-#	Other headers are reclassified as 'Other'. You can also
-#	refer to all the headers with 'All'.
+#	more configurable. A list of ACLs for each header name allows
+#	removal of specific header fields under specific conditions.
+#
+#	This option only applies to outgoing HTTP request headers (i.e.,
+#	headers sent by Squid to the next HTTP hop such as a cache peer
+#	or an origin server). The option has no effect during cache hit
+#	detection. The equivalent adaptation vectoring point in ICAP
+#	terminology is post-cache REQMOD.
+#
+#	The option is applied to individual outgoing request header
+#	fields. For each request header field F, Squid uses the first
+#	qualifying sets of request_header_access rules:
+#
+#	    1. Rules with header_name equal to F's name.
+#	    2. Rules with header_name 'Other', provided F's name is not
+#	       on the hard-coded list of commonly used HTTP header names.
+#	    3. Rules with header_name 'All'.
+#
+#	Within that qualifying rule set, rule ACLs are checked as usual.
+#	If ACLs of an "allow" rule match, the header field is allowed to
+#	go through as is. If ACLs of a "deny" rule match, the header is
+#	removed and request_header_replace is then checked to identify
+#	if the removed header has a replacement. If no rules within the
+#	set have matching ACLs, the header field is left as is.
 #
 #	For example, to achieve the same behavior as the old
 #	'http_anonymizer standard' option, you should use:
 #
 #		request_header_access From deny all
 #		request_header_access Referer deny all
-#		request_header_access Server deny all
 #		request_header_access User-Agent deny all
-#		request_header_access WWW-Authenticate deny all
-#		request_header_access Link deny all
 #
 #	Or, to reproduce the old 'http_anonymizer paranoid' feature
 #	you should use:
 #
-#		request_header_access Allow allow all
 #		request_header_access Authorization allow all
-#		request_header_access WWW-Authenticate allow all
 #		request_header_access Proxy-Authorization allow all
-#		request_header_access Proxy-Authenticate allow all
 #		request_header_access Cache-Control allow all
-#		request_header_access Content-Encoding allow all
 #		request_header_access Content-Length allow all
 #		request_header_access Content-Type allow all
 #		request_header_access Date allow all
-#		request_header_access Expires allow all
 #		request_header_access Host allow all
 #		request_header_access If-Modified-Since allow all
-#		request_header_access Last-Modified allow all
-#		request_header_access Location allow all
 #		request_header_access Pragma allow all
 #		request_header_access Accept allow all
 #		request_header_access Accept-Charset allow all
 #		request_header_access Accept-Encoding allow all
 #		request_header_access Accept-Language allow all
-#		request_header_access Content-Language allow all
-#		request_header_access Mime-Version allow all
-#		request_header_access Retry-After allow all
-#		request_header_access Title allow all
 #		request_header_access Connection allow all
 #		request_header_access All deny all
 #
-#	although many of those are HTTP reply headers, and so should be
-#	controlled with the reply_header_access directive.
+#	HTTP reply headers are controlled with the reply_header_access directive.
 #
-#	By default, all headers are allowed (no anonymizing is
-#	performed).
+#	By default, all headers are allowed (no anonymizing is performed).
 #Default:
-# none
+# No limits.
 
 #  TAG: reply_header_access
 #	Usage: reply_header_access header_name allow|deny [!]aclname ...
@@ -3465,25 +5224,13 @@ refresh_pattern .		0	20%	4320
 #	server to the client.
 #
 #	This is the same as request_header_access, but in the other
-#	direction.
-#
-#	This option replaces the old 'anonymize_headers' and the
-#	older 'http_anonymizer' option with something that is much
-#	more configurable. This new method creates a list of ACLs
-#	for each header, allowing you very fine-tuned header
-#	mangling.
-#
-#	You can only specify known headers for the header name.
-#	Other headers are reclassified as 'Other'. You can also
-#	refer to all the headers with 'All'.
+#	direction. Please see request_header_access for detailed
+#	documentation.
 #
 #	For example, to achieve the same behavior as the old
 #	'http_anonymizer standard' option, you should use:
 #
-#		reply_header_access From deny all
-#		reply_header_access Referer deny all
 #		reply_header_access Server deny all
-#		reply_header_access User-Agent deny all
 #		reply_header_access WWW-Authenticate deny all
 #		reply_header_access Link deny all
 #
@@ -3491,9 +5238,7 @@ refresh_pattern .		0	20%	4320
 #	you should use:
 #
 #		reply_header_access Allow allow all
-#		reply_header_access Authorization allow all
 #		reply_header_access WWW-Authenticate allow all
-#		reply_header_access Proxy-Authorization allow all
 #		reply_header_access Proxy-Authenticate allow all
 #		reply_header_access Cache-Control allow all
 #		reply_header_access Content-Encoding allow all
@@ -3501,29 +5246,22 @@ refresh_pattern .		0	20%	4320
 #		reply_header_access Content-Type allow all
 #		reply_header_access Date allow all
 #		reply_header_access Expires allow all
-#		reply_header_access Host allow all
-#		reply_header_access If-Modified-Since allow all
 #		reply_header_access Last-Modified allow all
 #		reply_header_access Location allow all
 #		reply_header_access Pragma allow all
-#		reply_header_access Accept allow all
-#		reply_header_access Accept-Charset allow all
-#		reply_header_access Accept-Encoding allow all
-#		reply_header_access Accept-Language allow all
 #		reply_header_access Content-Language allow all
-#		reply_header_access Mime-Version allow all
 #		reply_header_access Retry-After allow all
 #		reply_header_access Title allow all
+#		reply_header_access Content-Disposition allow all
 #		reply_header_access Connection allow all
 #		reply_header_access All deny all
 #
-#	although the HTTP request headers won't be usefully controlled
-#	by this directive -- see request_header_access for details.
+#	HTTP request headers are controlled with the request_header_access directive.
 #
 #	By default, all headers are allowed (no anonymizing is
 #	performed).
 #Default:
-# none
+# No limits.
 
 #  TAG: request_header_replace
 #	Usage:   request_header_replace header_name message
@@ -3531,8 +5269,7 @@ refresh_pattern .		0	20%	4320
 #
 #	This option allows you to change the contents of headers
 #	denied with request_header_access above, by replacing them
-#	with some fixed string. This replaces the old fake_user_agent
-#	option.
+#	with some fixed string.
 #
 #	This only applies to request headers, not reply headers.
 #
@@ -3554,6 +5291,57 @@ refresh_pattern .		0	20%	4320
 #Default:
 # none
 
+#  TAG: request_header_add
+#	Usage:   request_header_add field-name field-value acl1 [acl2] ...
+#	Example: request_header_add X-Client-CA "CA=%ssl::>cert_issuer" all
+#
+#	This option adds header fields to outgoing HTTP requests (i.e.,
+#	request headers sent by Squid to the next HTTP hop such as a
+#	cache peer or an origin server). The option has no effect during
+#	cache hit detection. The equivalent adaptation vectoring point
+#	in ICAP terminology is post-cache REQMOD.
+#
+#	Field-name is a token specifying an HTTP header name. If a
+#	standard HTTP header name is used, Squid does not check whether
+#	the new header conflicts with any existing headers or violates
+#	HTTP rules. If the request to be modified already contains a
+#	field with the same name, the old field is preserved but the
+#	header field values are not merged.
+#
+#	Field-value is either a token or a quoted string. If quoted
+#	string format is used, then the surrounding quotes are removed
+#	while escape sequences and %macros are processed.
+#
+#	In theory, all of the logformat codes can be used as %macros.
+#	However, unlike logging (which happens at the very end of
+#	transaction lifetime), the transaction may not yet have enough
+#	information to expand a macro when the new header value is needed.
+#	And some information may already be available to Squid but not yet
+#	committed where the macro expansion code can access it (report
+#	such instances!). The macro will be expanded into a single dash
+#	('-') in such cases. Not all macros have been tested.
+#
+#	One or more Squid ACLs may be specified to restrict header
+#	injection to matching requests. As always in squid.conf, all
+#	ACLs in an option ACL list must be satisfied for the insertion
+#	to happen. The request_header_add option supports fast ACLs
+#	only.
+#Default:
+# none
+
+#  TAG: note
+#	This option used to log custom information about the master
+#	transaction. For example, an admin may configure Squid to log
+#	which "user group" the transaction belongs to, where "user group"
+#	will be determined based on a set of ACLs and not [just]
+#	authentication information.
+#	Values of key/value pairs can be logged using %{key}note macros:
+#
+#	    note key value acl ...
+#	    logformat myFormat ... %{key}note ...
+#Default:
+# none
+
 #  TAG: relaxed_header_parser	on|off|warn
 #	In the default "on" setting Squid accepts certain forms
 #	of non-compliant HTTP messages where it is unambiguous
@@ -3569,15 +5357,32 @@ refresh_pattern .		0	20%	4320
 #Default:
 # relaxed_header_parser on
 
-#  TAG: ignore_expect_100	on|off
-#	This option makes Squid ignore any Expect: 100-continue header present
-#	in the request. RFC 2616 requires that Squid being unable to satisfy
-#	the response expectation MUST return a 417 error.
-#
-#	Note: Enabling this is a HTTP protocol violation, but some clients may
-#	not handle it well..
-#Default:
-# ignore_expect_100 off
+#  TAG: collapsed_forwarding	(on|off)
+#       When enabled, instead of forwarding each concurrent request for
+#       the same URL, Squid just sends the first of them. The other, so
+#       called "collapsed" requests, wait for the response to the first
+#       request and, if it happens to be cachable, use that response.
+#       Here, "concurrent requests" means "received after the first
+#       request headers were parsed and before the corresponding response
+#       headers were parsed".
+#
+#       This feature is disabled by default: enabling collapsed
+#       forwarding needlessly delays forwarding requests that look
+#       cachable (when they are collapsed) but then need to be forwarded
+#       individually anyway because they end up being for uncachable
+#       content. However, in some cases, such as acceleration of highly
+#       cachable content with periodic or grouped expiration times, the
+#       gains from collapsing [large volumes of simultaneous refresh
+#       requests] outweigh losses from such delays.
+#
+#       Squid collapses two kinds of requests: regular client requests
+#       received on one of the listening ports and internal "cache
+#       revalidation" requests which are triggered by those regular
+#       requests hitting a stale cached object. Revalidation collapsing
+#       is currently disabled for Squid instances containing SMP-aware
+#       disk or memory caches and for Vary-controlled cached objects.
+#Default:
+# collapsed_forwarding off
 
 # TIMEOUTS
 # -----------------------------------------------------------------------------
@@ -3604,25 +5409,46 @@ refresh_pattern .		0	20%	4320
 # peer_connect_timeout 30 seconds
 
 #  TAG: read_timeout	time-units
-#	The read_timeout is applied on server-side connections.  After
-#	each successful read(), the timeout will be extended by this
+#	Applied on peer server connections.
+#
+#	After each successful read(), the timeout will be extended by this
 #	amount.  If no data is read again after this amount of time,
-#	the request is aborted and logged with ERR_READ_TIMEOUT.  The
-#	default is 15 minutes.
+#	the request is aborted and logged with ERR_READ_TIMEOUT.
+#
+#	The default is 15 minutes.
 #Default:
 # read_timeout 15 minutes
 
+#  TAG: write_timeout	time-units
+#	This timeout is tracked for all connections that have data
+#	available for writing and are waiting for the socket to become
+#	ready. After each successful write, the timeout is extended by
+#	the configured amount. If Squid has data to write but the
+#	connection is not ready for the configured duration, the
+#	transaction associated with the connection is terminated. The
+#	default is 15 minutes.
+#Default:
+# write_timeout 15 minutes
+
 #  TAG: request_timeout
 #	How long to wait for complete HTTP request headers after initial
 #	connection establishment.
 #Default:
 # request_timeout 5 minutes
 
-#  TAG: persistent_request_timeout
+#  TAG: client_idle_pconn_timeout
 #	How long to wait for the next HTTP request on a persistent
-#	connection after the previous request completes.
+#	client connection after the previous request completes.
+#Default:
+# client_idle_pconn_timeout 2 minutes
+
+#  TAG: ftp_client_idle_timeout
+#	How long to wait for an FTP request on a connection to Squid ftp_port.
+#	Many FTP clients do not deal with idle connection closures well,
+#	necessitating a longer default timeout than client_idle_pconn_timeout
+#	used for incoming HTTP requests.
 #Default:
-# persistent_request_timeout 2 minutes
+# ftp_client_idle_timeout 30 minutes
 
 #  TAG: client_lifetime	time-units
 #	The maximum amount of time a client (browser) is allowed to
@@ -3658,11 +5484,11 @@ refresh_pattern .		0	20%	4320
 #Default:
 # half_closed_clients off
 
-#  TAG: pconn_timeout
+#  TAG: server_idle_pconn_timeout
 #	Timeout for idle persistent connections to servers and other
 #	proxies.
 #Default:
-# pconn_timeout 1 minute
+# server_idle_pconn_timeout 1 minute
 
 #  TAG: ident_timeout
 #	Maximum time to wait for IDENT lookups to complete.
@@ -3687,15 +5513,15 @@ refresh_pattern .		0	20%	4320
 
 #  TAG: cache_mgr
 #	Email-address of local cache manager who will receive
-#	mail if the cache dies.  The default is "webmaster."
+#	mail if the cache dies.  The default is "webmaster".
 #Default:
 # cache_mgr webmaster
 
 #  TAG: mail_from
 #	From: email-address for mail sent when the cache dies.
-#	The default is to use 'appname@unique_hostname'.
-#	Default appname value is "squid", can be changed into
-#	src/globals.h before building squid.
+#	The default is to use 'squid@unique_hostname'.
+#
+#	See also: unique_hostname directive.
 #Default:
 # none
 
@@ -3734,7 +5560,7 @@ refresh_pattern .		0	20%	4320
 #	Our preference is for administrators to configure a secure
 #	user account for squid with UID/GID matching system policies.
 #Default:
-# none
+# Use system group memberships of the cache_effective_user account
 
 #  TAG: httpd_suppress_version_string	on|off
 #	Suppress Squid version string info in HTTP headers and HTML error pages.
@@ -3748,14 +5574,14 @@ refresh_pattern .		0	20%	4320
 #	get errors about IP-forwarding you must set them to have individual
 #	names with this setting.
 #Default:
-# visible_hostname localhost
+# Automatically detect the system host name
 
 #  TAG: unique_hostname
 #	If you want to have multiple machines with the same
 #	'visible_hostname' you must give each machine a different
 #	'unique_hostname' so forwarding loops can be detected.
 #Default:
-# none
+# Copy the value from visible_hostname
 
 #  TAG: hostname_aliases
 #	A list of other DNS names your cache has.
@@ -3794,33 +5620,32 @@ refresh_pattern .		0	20%	4320
 #	available on the Web at http://www.ircache.net/Cache/Tracker/.
 
 #  TAG: announce_period
-#	This is how frequently to send cache announcements.  The
-#	default is `0' which disables sending the announcement
-#	messages.
+#	This is how frequently to send cache announcements.
 #
 #	To enable announcing your cache, just set an announce period.
 #
 #	Example:
 #		announce_period 1 day
 #Default:
-# announce_period 0
+# Announcement messages disabled.
 
 #  TAG: announce_host
+#	Set the hostname where announce registration messages will be sent.
+#
+#	See also announce_port and announce_file
 #Default:
 # announce_host tracker.ircache.net
 
 #  TAG: announce_file
+#	The contents of this file will be included in the announce
+#	registration messages.
 #Default:
 # none
 
 #  TAG: announce_port
-#	announce_host and announce_port set the hostname and port
-#	number where the registration message will be sent.
+#	Set the port where announce registration messages will be sent.
 #
-#	Hostname will default to 'tracker.ircache.net' and port will
-#	default default to 3131.  If the 'filename' argument is given,
-#	the contents of that file will be included in the announce
-#	message.
+#	See also announce_host and announce_file
 #Default:
 # announce_port 3131
 
@@ -3833,10 +5658,12 @@ refresh_pattern .		0	20%	4320
 #	a farm of surrogates may all perform the same tasks, they may share
 #	an identification token.
 #Default:
-# httpd_accel_surrogate_id unset-id
+# visible_hostname is used if no specific ID is set.
 
 #  TAG: http_accel_surrogate_remote	on|off
-#	Remote surrogates (such as those in a CDN) honour Surrogate-Control: no-store-remote.
+#	Remote surrogates (such as those in a CDN) honour the header
+#	"Surrogate-Control: no-store-remote".
+#
 #	Set this to on to have squid behave as a remote surrogate.
 #Default:
 # http_accel_surrogate_remote off
@@ -3855,6 +5682,9 @@ refresh_pattern .		0	20%	4320
 #	This represents the number of delay pools to be used.  For example,
 #	if you have one class 2 delay pool and one class 3 delays pool, you
 #	have a total of 2 delay pools.
+#
+#	See also delay_parameters, delay_class, delay_access for pool
+#	configuration details.
 #Default:
 # delay_pools 0
 
@@ -3907,6 +5737,11 @@ refresh_pattern .		0	20%	4320
 #
 #	NOTE-2: Due to the use of bitmasks in class 2,3,4 pools they only apply to
 #		IPv4 traffic. Class 1 and 5 pools may be used with IPv6 traffic.
+#
+#	This clause only supports fast acl types.
+#	See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
+#
+#	See also delay_parameters and delay_access.
 #Default:
 # none
 
@@ -3921,14 +5756,16 @@ refresh_pattern .		0	20%	4320
 #	For example, if you want some_big_clients in delay
 #	pool 1 and lotsa_little_clients in delay pool 2:
 #
-#Example:
-# delay_access 1 allow some_big_clients
-# delay_access 1 deny all
-# delay_access 2 allow lotsa_little_clients
-# delay_access 2 deny all
-# delay_access 3 allow authenticated_clients
+#		delay_access 1 allow some_big_clients
+#		delay_access 1 deny all
+#		delay_access 2 allow lotsa_little_clients
+#		delay_access 2 deny all
+#		delay_access 3 allow authenticated_clients
+#
+#	See also delay_parameters and delay_class.
+#
 #Default:
-# none
+# Deny using the pool, unless allow rules exist in squid.conf for the pool.
 
 #  TAG: delay_parameters
 #	This defines the parameters for a delay pool.  Each delay pool has
@@ -3936,23 +5773,23 @@ refresh_pattern .		0	20%	4320
 #	description of delay_class.
 #
 #	For a class 1 delay pool, the syntax is:
-#		delay_pools pool 1
+#		delay_class pool 1
 #		delay_parameters pool aggregate
 #
 #	For a class 2 delay pool:
-#		delay_pools pool 2
+#		delay_class pool 2
 #		delay_parameters pool aggregate individual
 #
 #	For a class 3 delay pool:
-#		delay_pools pool 3
+#		delay_class pool 3
 #		delay_parameters pool aggregate network individual
 #
 #	For a class 4 delay pool:
-#		delay_pools pool 4
+#		delay_class pool 4
 #		delay_parameters pool aggregate network individual user
 #
 #	For a class 5 delay pool:
-#		delay_pools pool 5
+#		delay_class pool 5
 #		delay_parameters pool tagrate
 #
 #	The option variables are:
@@ -3988,11 +5825,11 @@ refresh_pattern .		0	20%	4320
 #	above example, and is being used to strictly limit each host to 64Kbit/sec
 #	(plus overheads), with no overall limit, the line is:
 #
-#		delay_parameters 1 -1/-1 8000/8000
+#		delay_parameters 1 none 8000/8000
 #
-#	Note that 8 x 8000 KByte/sec -> 64Kbit/sec.
+#	Note that 8 x 8K Byte/sec -> 64K bit/sec.
 #
-#	Note that the figure -1 is used to represent "unlimited".
+#	Note that the word 'none' is used to represent no limit.
 #
 #
 #	And, if delay pool number 2 is a class 3 delay pool as in the above
@@ -4005,15 +5842,19 @@ refresh_pattern .		0	20%	4320
 #
 #		delay_parameters 2 32000/32000 8000/8000 600/8000
 #
-#	Note that 8 x 32000 KByte/sec -> 256Kbit/sec.
-#		  8 x  8000 KByte/sec ->  64Kbit/sec.
-#		  8 x   600 Byte/sec  -> 4800bit/sec.
+#	Note that 8 x  32K Byte/sec ->  256K bit/sec.
+#		  8 x   8K Byte/sec ->   64K bit/sec.
+#		  8 x 600  Byte/sec -> 4800  bit/sec.
 #
 #
 #	Finally, for a class 4 delay pool as in the example - each user will
 #	be limited to 128Kbits/sec no matter how many workstations they are logged into.:
 #
 #		delay_parameters 4 32000/32000 8000/8000 600/64000 16000/16000
+#
+#
+#	See also delay_class and delay_access.
+#
 #Default:
 # none
 
@@ -4026,6 +5867,94 @@ refresh_pattern .		0	20%	4320
 #Default:
 # delay_initial_bucket_level 50
 
+# CLIENT DELAY POOL PARAMETERS
+# -----------------------------------------------------------------------------
+
+#  TAG: client_delay_pools
+#	This option specifies the number of client delay pools used. It must
+#	preceed other client_delay_* options.
+#
+#	Example:
+#		client_delay_pools 2
+#
+#	See also client_delay_parameters and client_delay_access.
+#Default:
+# client_delay_pools 0
+
+#  TAG: client_delay_initial_bucket_level	(percent, 0-no_limit)
+#	This option determines the initial bucket size as a percentage of
+#	max_bucket_size from client_delay_parameters. Buckets are created
+#	at the time of the "first" connection from the matching IP. Idle
+#	buckets are periodically deleted up.
+#
+#	You can specify more than 100 percent but note that such "oversized"
+#	buckets are not refilled until their size goes down to max_bucket_size
+#	from client_delay_parameters.
+#
+#	Example:
+#		client_delay_initial_bucket_level 50
+#Default:
+# client_delay_initial_bucket_level 50
+
+#  TAG: client_delay_parameters
+#
+#	This option configures client-side bandwidth limits using the
+#	following format:
+#
+#	    client_delay_parameters pool speed_limit max_bucket_size
+#
+#	pool is an integer ID used for client_delay_access matching.
+#
+#	speed_limit is bytes added to the bucket per second.
+#
+#	max_bucket_size is the maximum size of a bucket, enforced after any
+#	speed_limit additions.
+#
+#	Please see the delay_parameters option for more information and
+#	examples.
+#
+#	Example:
+#		client_delay_parameters 1 1024 2048
+#		client_delay_parameters 2 51200 16384
+#
+#	See also client_delay_access.
+#
+#Default:
+# none
+
+#  TAG: client_delay_access
+#	This option determines the client-side delay pool for the
+#	request:
+#
+#	    client_delay_access pool_ID allow|deny acl_name
+#
+#	All client_delay_access options are checked in their pool ID
+#	order, starting with pool 1. The first checked pool with allowed
+#	request is selected for the request. If no ACL matches or there
+#	are no client_delay_access options, the request bandwidth is not
+#	limited.
+#
+#	The ACL-selected pool is then used to find the
+#	client_delay_parameters for the request. Client-side pools are
+#	not used to aggregate clients. Clients are always aggregated
+#	based on their source IP addresses (one bucket per source IP).
+#
+#	This clause only supports fast acl types.
+#	See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
+#	Additionally, only the client TCP connection details are available.
+#	ACLs testing HTTP properties will not work.
+#
+#	Please see delay_access for more examples.
+#
+#	Example:
+#		client_delay_access 1 allow low_rate_network
+#		client_delay_access 2 allow vips_network
+#
+#
+#	See also client_delay_parameters and client_delay_pools.
+#Default:
+# Deny use of the pool, unless allow rules exist in squid.conf for the pool.
+
 # WCCPv1 AND WCCPv2 CONFIGURATION OPTIONS
 # -----------------------------------------------------------------------------
 
@@ -4040,7 +5969,7 @@ refresh_pattern .		0	20%	4320
 #	only one of the two may be used at the same time and defines
 #	which version of WCCP to use.
 #Default:
-# wccp_router any_addr
+# WCCP disabled.
 
 #  TAG: wccp2_router
 #	Use this option to define your WCCP ``home'' router for
@@ -4053,7 +5982,7 @@ refresh_pattern .		0	20%	4320
 #	only one of the two may be used at the same time and defines
 #	which version of WCCP to use.
 #Default:
-# none
+# WCCPv2 disabled.
 
 #  TAG: wccp_version
 #	This directive is only relevant if you need to set up WCCP(v1)
@@ -4110,7 +6039,7 @@ refresh_pattern .		0	20%	4320
 #	Valid values are as follows:
 #
 #	hash - Hash assignment
-#	mask  - Mask assignment
+#	mask - Mask assignment
 #
 #	As a general rule, cisco routers support the hash assignment method
 #	and cisco switches support the mask assignment method.
@@ -4138,7 +6067,7 @@ refresh_pattern .		0	20%	4320
 #					# fleshed out with subsequent options.
 #	wccp2_service standard 0 password=foo
 #Default:
-# wccp2_service standard 0
+# Use the 'web-cache' standard service.
 
 #  TAG: wccp2_service_info
 #	Dynamic WCCPv2 services require further information to define the
@@ -4175,8 +6104,12 @@ refresh_pattern .		0	20%	4320
 # wccp2_weight 10000
 
 #  TAG: wccp_address
+#	Use this option if you require WCCPv2 to use a specific
+#	interface address.
+#
+#	The default behavior is to not bind to any specific address.
 #Default:
-# wccp_address 0.0.0.0
+# Address selected by the operating system.
 
 #  TAG: wccp2_address
 #	Use this option if you require WCCP to use a specific
@@ -4184,7 +6117,7 @@ refresh_pattern .		0	20%	4320
 #
 #	The default behavior is to not bind to any specific address.
 #Default:
-# wccp2_address 0.0.0.0
+# Address selected by the operating system.
 
 # PERSISTENT CONNECTION HANDLING
 # -----------------------------------------------------------------------------
@@ -4192,14 +6125,16 @@ refresh_pattern .		0	20%	4320
 # Also see "pconn_timeout" in the TIMEOUTS section
 
 #  TAG: client_persistent_connections
+#	Persistent connection support for clients.
+#	Squid uses persistent connections (when allowed). You can use
+#	this option to disable persistent connections with clients.
 #Default:
 # client_persistent_connections on
 
 #  TAG: server_persistent_connections
-#	Persistent connection support for clients and servers.  By
-#	default, Squid uses persistent connections (when allowed)
-#	with its clients and servers.  You can use these options to
-#	disable persistent connections with clients and/or servers.
+#	Persistent connection support for servers.
+#	Squid uses persistent connections (when allowed). You can use
+#	this option to disable persistent connections with servers.
 #Default:
 # server_persistent_connections on
 
@@ -4275,7 +6210,7 @@ refresh_pattern .		0	20%	4320
 #	Example:
 #		snmp_port 3401
 #Default:
-# snmp_port 0
+# SNMP disabled.
 
 #  TAG: snmp_access
 #	Allowing or denying access to the SNMP port.
@@ -4287,26 +6222,29 @@ refresh_pattern .		0	20%	4320
 #
 #	This clause only supports fast acl types.
 #	See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
+#
 #Example:
 # snmp_access allow snmppublic localhost
 # snmp_access deny all
 #Default:
-# snmp_access deny all
+# Deny, unless rules exist in squid.conf.
 
 #  TAG: snmp_incoming_address
-#Default:
-# snmp_incoming_address any_addr
-
-#  TAG: snmp_outgoing_address
 #	Just like 'udp_incoming_address', but for the SNMP port.
 #
 #	snmp_incoming_address	is used for the SNMP socket receiving
 #				messages from SNMP agents.
-#	snmp_outgoing_address	is used for SNMP packets returned to SNMP
-#				agents.
 #
 #	The default snmp_incoming_address is to listen on all
 #	available network interfaces.
+#Default:
+# Accept SNMP packets from all machine interfaces.
+
+#  TAG: snmp_outgoing_address
+#	Just like 'udp_outgoing_address', but for the SNMP port.
+#
+#	snmp_outgoing_address	is used for SNMP packets returned to SNMP
+#				agents.
 #
 #	If snmp_outgoing_address is not set it will use the same socket
 #	as snmp_incoming_address. Only change this if you want to have
@@ -4314,9 +6252,9 @@ refresh_pattern .		0	20%	4320
 #	listens for SNMP queries.
 #
 #	NOTE, snmp_incoming_address and snmp_outgoing_address can not have
-#	the same value since they both use port 3401.
+#	the same value since they both use the same port.
 #Default:
-# snmp_outgoing_address no_addr
+# Use snmp_incoming_address or an address selected by the operating system.
 
 # ICP OPTIONS
 # -----------------------------------------------------------------------------
@@ -4324,22 +6262,21 @@ refresh_pattern .		0	20%	4320
 #  TAG: icp_port
 #	The port number where Squid sends and receives ICP queries to
 #	and from neighbor caches.  The standard UDP port for ICP is 3130.
-#	Default is disabled (0).
 #
 #	Example:
 #		icp_port 3130
 #Default:
-# icp_port 0
+# ICP disabled.
 
 #  TAG: htcp_port
 #	The port number where Squid sends and receives HTCP queries to
 #	and from neighbor caches.  To turn it on you want to set it to
-#	4827. By default it is set to "0" (disabled).
+#	4827.
 #
 #	Example:
 #		htcp_port 4827
 #Default:
-# htcp_port 0
+# HTCP disabled.
 
 #  TAG: log_icp_queries	on|off
 #	If set, ICP queries are logged to access.log. You may wish
@@ -4365,7 +6302,7 @@ refresh_pattern .		0	20%	4320
 #	NOTE, udp_incoming_address and udp_outgoing_address can not
 #	have the same value since they both use the same port.
 #Default:
-# udp_incoming_address any_addr
+# Accept packets from all machine interfaces.
 
 #  TAG: udp_outgoing_address
 #	udp_outgoing_address	is used for UDP packets sent out to other
@@ -4386,7 +6323,7 @@ refresh_pattern .		0	20%	4320
 #	NOTE, udp_incoming_address and udp_outgoing_address can not
 #	have the same value since they both use the same port.
 #Default:
-# udp_outgoing_address no_addr
+# Use udp_incoming_address or an address selected by the operating system.
 
 #  TAG: icp_hit_stale	on|off
 #	If you want to return ICP_HIT for stale cache objects, set this
@@ -4405,21 +6342,33 @@ refresh_pattern .		0	20%	4320
 #Default:
 # minimum_direct_hops 4
 
-#  TAG: minimum_direct_rtt
+#  TAG: minimum_direct_rtt	(msec)
 #	If using the ICMP pinging stuff, do direct fetches for sites
 #	which are no more than this many rtt milliseconds away.
 #Default:
 # minimum_direct_rtt 400
 
 #  TAG: netdb_low
+#	The low water mark for the ICMP measurement database.
+#
+#	Note: high watermark controlled by netdb_high directive.
+#
+#	These watermarks are counts, not percents.  The defaults are
+#	(low) 900 and (high) 1000.  When the high water mark is
+#	reached, database entries will be deleted until the low
+#	mark is reached.
 #Default:
 # netdb_low 900
 
 #  TAG: netdb_high
-#	The low and high water marks for the ICMP measurement
-#	database.  These are counts, not percents.  The defaults are
-#	900 and 1000.  When the high water mark is reached, database
-#	entries will be deleted until the low mark is reached.
+#	The high water mark for the ICMP measurement database.
+#
+#	Note: low watermark controlled by netdb_low directive.
+#
+#	These watermarks are counts, not percents.  The defaults are
+#	(low) 900 and (high) 1000.  When the high water mark is
+#	reached, database entries will be deleted until the low
+#	mark is reached.
 #Default:
 # netdb_high 1000
 
@@ -4462,7 +6411,7 @@ refresh_pattern .		0	20%	4320
 #
 #		icp_query_timeout 2000
 #Default:
-# icp_query_timeout 0
+# Dynamic detection.
 
 #  TAG: maximum_icp_query_timeout	(msec)
 #	Normally the ICP query timeout is determined dynamically.  But
@@ -4528,7 +6477,7 @@ refresh_pattern .		0	20%	4320
 #	Do not enable this option unless you are are absolutely
 #	certain you understand what you are doing.
 #Default:
-# mcast_miss_addr no_addr
+# disabled.
 
 #  TAG: mcast_miss_ttl
 # Note: This option is only available if Squid is rebuilt with the
@@ -4618,7 +6567,7 @@ refresh_pattern .		0	20%	4320
 #	The squid developers working on translations are happy to supply drop-in
 #	translated error files in exchange for any new language contributions.
 #Default:
-# none
+# Send error pages in the clients preferred language
 
 #  TAG: error_default_language
 #	Set the default language which squid will send error pages in
@@ -4632,7 +6581,7 @@ refresh_pattern .		0	20%	4320
 #	translations for any language see the squid wiki for details.
 #	http://wiki.squid-cache.org/Translations
 #Default:
-# none
+# Generate English language pages.
 
 #  TAG: error_log_languages
 #	Log to cache.log what languages users are attempting to
@@ -4687,17 +6636,47 @@ refresh_pattern .		0	20%	4320
 #	  the first authentication related acl encountered
 #	- When none of the http_access lines matches. It's then the last
 #	  acl processed on the last http_access line.
+#	- When the decision to deny access was made by an adaptation service,
+#	  the acl name is the corresponding eCAP or ICAP service_name.
 #
 #	NP: If providing your own custom error pages with error_directory
 #	    you may also specify them by your custom file name:
 #	    Example: deny_info ERR_CUSTOM_ACCESS_DENIED bad_guys
 #
-#	Alternatively you can specify an error URL. The browsers will
-#	get redirected (302 or 307) to the specified URL. %s in the redirection
-#	URL will be replaced by the requested URL.
+#	By defaut Squid will send "403 Forbidden". A different 4xx or 5xx
+#	may be specified by prefixing the file name with the code and a colon.
+#	e.g. 404:ERR_CUSTOM_ACCESS_DENIED
 #
 #	Alternatively you can tell Squid to reset the TCP connection
 #	by specifying TCP_RESET.
+#
+#	Or you can specify an error URL or URL pattern. The browsers will
+#	get redirected to the specified URL after formatting tags have
+#	been replaced. Redirect will be done with 302 or 307 according to
+#	HTTP/1.1 specs. A different 3xx code may be specified by prefixing
+#	the URL. e.g. 303:http://example.com/
+#
+#	URL FORMAT TAGS:
+#		%a	- username (if available. Password NOT included)
+#		%B	- FTP path URL
+#		%e	- Error number
+#		%E	- Error description
+#		%h	- Squid hostname
+#		%H	- Request domain name
+#		%i	- Client IP Address
+#		%M	- Request Method
+#		%o	- Message result from external ACL helper
+#		%p	- Request Port number
+#		%P	- Request Protocol name
+#		%R	- Request URL path
+#		%T	- Timestamp in RFC 1123 format
+#		%U	- Full canonical URL from client
+#			  (HTTPS URLs terminate with *)
+#		%u	- Full canonical URL from client
+#		%w	- Admin email from squid.conf
+#		%x	- Error name
+#		%%	- Literal percent (%) code
+#
 #Default:
 # none
 
@@ -4706,18 +6685,18 @@ refresh_pattern .		0	20%	4320
 
 #  TAG: nonhierarchical_direct
 #	By default, Squid will send any non-hierarchical requests
-#	(matching hierarchy_stoplist or not cacheable request type) direct
-#	to origin servers.
+#	(not cacheable request type) direct to origin servers.
 #
-#	If you set this to off, Squid will prefer to send these
+#	When this is set to "off", Squid will prefer to send these
 #	requests to parents.
 #
 #	Note that in most configurations, by turning this off you will only
 #	add latency to these request without any improvement in global hit
 #	ratio.
 #
-#	If you are inside an firewall see never_direct instead of
-#	this directive.
+#	This option only sets a preference. If the parent is unavailable a
+#	direct connection to the origin server may still be attempted. To
+#	completely prevent direct connections use never_direct.
 #Default:
 # nonhierarchical_direct on
 
@@ -4736,6 +6715,29 @@ refresh_pattern .		0	20%	4320
 #Default:
 # prefer_direct off
 
+#  TAG: cache_miss_revalidate	on|off
+#	RFC 7232 defines a conditional request mechanism to prevent
+#	response objects being unnecessarily transferred over the network.
+#	If that mechanism is used by the client and a cache MISS occurs
+#	it can prevent new cache entries being created.
+#
+#	This option determines whether Squid on cache MISS will pass the
+#	client revalidation request to the server or tries to fetch new
+#	content for caching. It can be useful while the cache is mostly
+#	empty to more quickly have the cache populated by generating
+#	non-conditional GETs.
+#
+#	When set to 'on' (default), Squid will pass all client If-* headers
+#	to the server. This permits server responses without a cacheable
+#	payload to be delivered and on MISS no new cache entry is created.
+#
+#	When set to 'off' and if the request is cacheable, Squid will
+#	remove the clients If-Modified-Since and If-None-Match headers from
+#	the request sent to the server. This requests a 200 status response
+#	from the server to create a new cache entry with.
+#Default:
+# cache_miss_revalidate on
+
 #  TAG: always_direct
 #	Usage: always_direct allow|deny [!]aclname ...
 #
@@ -4776,7 +6778,7 @@ refresh_pattern .		0	20%	4320
 #	This clause supports both fast and slow acl types.
 #	See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
 #Default:
-# none
+# Prevent any cache_peer being used for this request.
 
 #  TAG: never_direct
 #	Usage: never_direct allow|deny [!]aclname ...
@@ -4805,37 +6807,52 @@ refresh_pattern .		0	20%	4320
 #	This clause supports both fast and slow acl types.
 #	See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
 #Default:
-# none
+# Allow DNS results to be used for this request.
 
 # ADVANCED NETWORKING OPTIONS
 # -----------------------------------------------------------------------------
 
-#  TAG: incoming_icp_average
+#  TAG: incoming_udp_average
+#	Heavy voodoo here.  I can't even believe you are reading this.
+#	Are you crazy?  Don't even think about adjusting these unless
+#	you understand the algorithms in comm_select.c first!
 #Default:
-# incoming_icp_average 6
+# incoming_udp_average 6
 
-#  TAG: incoming_http_average
+#  TAG: incoming_tcp_average
+#	Heavy voodoo here.  I can't even believe you are reading this.
+#	Are you crazy?  Don't even think about adjusting these unless
+#	you understand the algorithms in comm_select.c first!
 #Default:
-# incoming_http_average 4
+# incoming_tcp_average 4
 
 #  TAG: incoming_dns_average
+#	Heavy voodoo here.  I can't even believe you are reading this.
+#	Are you crazy?  Don't even think about adjusting these unless
+#	you understand the algorithms in comm_select.c first!
 #Default:
 # incoming_dns_average 4
 
-#  TAG: min_icp_poll_cnt
+#  TAG: min_udp_poll_cnt
+#	Heavy voodoo here.  I can't even believe you are reading this.
+#	Are you crazy?  Don't even think about adjusting these unless
+#	you understand the algorithms in comm_select.c first!
 #Default:
-# min_icp_poll_cnt 8
+# min_udp_poll_cnt 8
 
 #  TAG: min_dns_poll_cnt
+#	Heavy voodoo here.  I can't even believe you are reading this.
+#	Are you crazy?  Don't even think about adjusting these unless
+#	you understand the algorithms in comm_select.c first!
 #Default:
 # min_dns_poll_cnt 8
 
-#  TAG: min_http_poll_cnt
+#  TAG: min_tcp_poll_cnt
 #	Heavy voodoo here.  I can't even believe you are reading this.
 #	Are you crazy?  Don't even think about adjusting these unless
 #	you understand the algorithms in comm_select.c first!
 #Default:
-# min_http_poll_cnt 8
+# min_tcp_poll_cnt 8
 
 #  TAG: accept_filter
 #	FreeBSD:
@@ -4880,14 +6897,14 @@ refresh_pattern .		0	20%	4320
 #	WARNING: This may noticably slow down traffic received via external proxies
 #	or NAT devices and cause them to rebound error messages back to their clients.
 #Default:
-# client_ip_max_connections -1
+# No limit.
 
 #  TAG: tcp_recv_bufsize	(bytes)
 #	Size of receive buffer to set for TCP sockets.  Probably just
-#	as easy to change your kernel's default.  Set to zero to use
-#	the default buffer size.
+#	as easy to change your kernel's default.
+#	Omit from squid.conf to use the default buffer size.
 #Default:
-# tcp_recv_bufsize 0 bytes
+# Use operating system TCP defaults.
 
 # ICAP OPTIONS
 # -----------------------------------------------------------------------------
@@ -4913,22 +6930,36 @@ refresh_pattern .		0	20%	4320
 #	an established, active ICAP connection before giving up and
 #	either terminating the HTTP transaction or bypassing the
 #	failure.
-#
-#	The default is read_timeout.
 #Default:
-# none
+# Use read_timeout.
 
-#  TAG: icap_service_failure_limit
+#  TAG: icap_service_failure_limit	limit [in memory-depth time-units]
 #	The limit specifies the number of failures that Squid tolerates
 #	when establishing a new TCP connection with an ICAP service. If
 #	the number of failures exceeds the limit, the ICAP service is
 #	not used for new ICAP requests until it is time to refresh its
-#	OPTIONS. The per-service failure counter is reset to zero each
-#	time Squid fetches new service OPTIONS.
+#	OPTIONS.
 #
 #	A negative value disables the limit. Without the limit, an ICAP
 #	service will not be considered down due to connectivity failures
 #	between ICAP OPTIONS requests.
+#
+#	Squid forgets ICAP service failures older than the specified
+#	value of memory-depth. The memory fading algorithm 
+#	is approximate because Squid does not remember individual 
+#	errors but groups them instead, splitting the option
+#	value into ten time slots of equal length.
+#
+#	When memory-depth is 0 and by default this option has no 
+#	effect on service failure expiration.
+#
+#	Squid always forgets failures when updating service settings
+#	using an ICAP OPTIONS transaction, regardless of this option
+#	setting.
+#
+#	For example,
+#		# suspend service usage after 10 failures in 5 seconds:
+#		icap_service_failure_limit 10 in 5 seconds
 #Default:
 # icap_service_failure_limit 10
 
@@ -4962,10 +6993,26 @@ refresh_pattern .		0	20%	4320
 
 #  TAG: icap_preview_size
 #	The default size of preview data to be sent to the ICAP server.
-#	-1 means no preview. This value might be overwritten on a per server
-#	basis by OPTIONS requests.
+#	This value might be overwritten on a per server basis by OPTIONS requests.
 #Default:
-# icap_preview_size -1
+# No preview sent.
+
+#  TAG: icap_206_enable	on|off
+#	206 (Partial Content) responses is an ICAP extension that allows the
+#	ICAP agents to optionally combine adapted and original HTTP message
+#	content. The decision to combine is postponed until the end of the
+#	ICAP response. Squid supports Partial Content extension by default.
+#
+#	Activation of the Partial Content extension is negotiated with each
+#	ICAP service during OPTIONS exchange. Most ICAP servers should handle
+#	negotation correctly even if they do not support the extension, but
+#	some might fail. To disable Partial Content support for all ICAP
+#	services and to avoid any negotiation, set this option to "off".
+#
+#	Example:
+#	    icap_206_enable off
+#Default:
+# icap_206_enable on
 
 #  TAG: icap_default_options_ttl
 #	The default TTL value for ICAP OPTIONS responses that don't have
@@ -4979,25 +7026,27 @@ refresh_pattern .		0	20%	4320
 #Default:
 # icap_persistent_connections on
 
-#  TAG: icap_send_client_ip	on|off
+#  TAG: adaptation_send_client_ip	on|off
 #	If enabled, Squid shares HTTP client IP information with adaptation
 #	services. For ICAP, Squid adds the X-Client-IP header to ICAP requests.
 #	For eCAP, Squid sets the libecap::metaClientIp transaction option.
 #
 #	See also: adaptation_uses_indirect_client
 #Default:
-# icap_send_client_ip off
+# adaptation_send_client_ip off
 
-#  TAG: icap_send_client_username	on|off
+#  TAG: adaptation_send_username	on|off
 #	This sends authenticated HTTP client username (if available) to
-#	the ICAP service. The username value is encoded based on the
+#	the adaptation service.
+#
+#	For ICAP, the username value is encoded based on the
 #	icap_client_username_encode option and is sent using the header
 #	specified by the icap_client_username_header option.
 #Default:
-# icap_send_client_username off
+# adaptation_send_username off
 
 #  TAG: icap_client_username_header
-#	ICAP request header name to use for send_client_username.
+#	ICAP request header name to use for adaptation_send_username.
 #Default:
 # icap_client_username_header X-Client-Username
 
@@ -5009,17 +7058,19 @@ refresh_pattern .		0	20%	4320
 #  TAG: icap_service
 #	Defines a single ICAP service using the following format:
 #
-#	icap_service service_name vectoring_point [options] service_url
+#	icap_service id vectoring_point uri [option ...]
 #
-#	service_name: ID
-#		an opaque identifier which must be unique in squid.conf
+#	id: ID
+#		an opaque identifier or name which is used to direct traffic to
+#		this specific service. Must be unique among all adaptation
+#		services in squid.conf.
 #
 #	vectoring_point: reqmod_precache|reqmod_postcache|respmod_precache|respmod_postcache
 #		This specifies at which point of transaction processing the
 #		ICAP service should be activated. *_postcache vectoring points
 #		are not yet supported.
 #
-#	service_url: icap://servername:port/servicepath
+#	uri: icap://servername:port/servicepath
 #		ICAP server and service location.
 #
 #	ICAP does not allow a single service to handle both REQMOD and RESPMOD
@@ -5028,6 +7079,8 @@ refresh_pattern .		0	20%	4320
 #	can even specify multiple identical services as long as their
 #	service_names differ.
 #
+#	To activate a service, use the adaptation_access directive. To group
+#	services, use adaptation_service_chain and adaptation_service_set.
 #
 #	Service options are separated by white space. ICAP services support
 #	the following name=value options:
@@ -5049,11 +7102,12 @@ refresh_pattern .		0	20%	4320
 #		returning a chain of services to be used next. The services
 #		are specified using the X-Next-Services ICAP response header
 #		value, formatted as a comma-separated list of service names.
-#		Each named service should be configured in squid.conf and
-#		should have the same method and vectoring point as the current
-#		ICAP transaction.  Services violating these rules are ignored.
-#		An empty X-Next-Services value results in an empty plan which
-#		ends the current adaptation. 
+#		Each named service should be configured in squid.conf. Other
+#		services are ignored. An empty X-Next-Services value results
+#		in an empty plan which ends the current adaptation.
+#
+#		Dynamic adaptation plan may cross or cover multiple supported
+#		vectoring points in their natural processing order.
 #
 #		Routing is not allowed by default: the ICAP X-Next-Services
 #		response header is ignored.
@@ -5063,12 +7117,32 @@ refresh_pattern .		0	20%	4320
 #		is to use IPv4-only connections. When set to 'on' this option will
 #		make Squid use IPv6-only connections to contact this ICAP service.
 #
+#	on-overload=block|bypass|wait|force
+#		If the service Max-Connections limit has been reached, do
+#		one of the following for each new ICAP transaction:
+#		  * block:  send an HTTP error response to the client
+#		  * bypass: ignore the "over-connected" ICAP service
+#		  * wait:   wait (in a FIFO queue) for an ICAP connection slot
+#		  * force:  proceed, ignoring the Max-Connections limit 
+#
+#		In SMP mode with N workers, each worker assumes the service
+#		connection limit is Max-Connections/N, even though not all
+#		workers may use a given service.
+#
+#		The default value is "bypass" if service is bypassable,
+#		otherwise it is set to "wait".
+#		
+#
+#	max-conn=number
+#		Use the given number as the Max-Connections limit, regardless
+#		of the Max-Connections value given by the service, if any.
+#
 #	Older icap_service format without optional named parameters is
 #	deprecated but supported for backward compatibility.
 #
 #Example:
-#icap_service svcBlocker reqmod_precache bypass=0 icap://icap1.mydomain.net:1344/reqmod
-#icap_service svcLogger reqmod_precache routing=on icap://icap2.mydomain.net:1344/respmod
+#icap_service svcBlocker reqmod_precache icap://icap1.mydomain.net:1344/reqmod bypass=0
+#icap_service svcLogger reqmod_precache icap://icap2.mydomain.net:1344/respmod routing=on
 #Default:
 # none
 
@@ -5094,38 +7168,65 @@ refresh_pattern .		0	20%	4320
 # -----------------------------------------------------------------------------
 
 #  TAG: ecap_enable	on|off
-# Note: This option is only available if Squid is rebuilt with the
-#       --enable-ecap option
-#
 #	Controls whether eCAP support is enabled.
 #Default:
 # ecap_enable off
 
 #  TAG: ecap_service
-# Note: This option is only available if Squid is rebuilt with the
-#       --enable-ecap option
-#
 #	Defines a single eCAP service
 #
-#	ecap_service servicename vectoring_point bypass service_url
+#	ecap_service id vectoring_point uri [option ...]
 #
-#	vectoring_point = reqmod_precache|reqmod_postcache|respmod_precache|respmod_postcache
+#        id: ID
+#		an opaque identifier or name which is used to direct traffic to
+#		this specific service. Must be unique among all adaptation
+#		services in squid.conf.
+#
+#	vectoring_point: reqmod_precache|reqmod_postcache|respmod_precache|respmod_postcache
 #		This specifies at which point of transaction processing the
 #		eCAP service should be activated. *_postcache vectoring points
 #		are not yet supported.
-#	bypass = 1|0
-#		If set to 1, the eCAP service is treated as optional. If the
-#		service cannot be reached or malfunctions, Squid will try to
-#		ignore any errors and process the message as if the service
+#
+#	uri: ecap://vendor/service_name?custom&cgi=style&parameters=optional
+#		Squid uses the eCAP service URI to match this configuration
+#		line with one of the dynamically loaded services. Each loaded
+#		eCAP service must have a unique URI. Obtain the right URI from
+#		the service provider.
+#
+#	To activate a service, use the adaptation_access directive. To group
+#	services, use adaptation_service_chain and adaptation_service_set.
+#
+#	Service options are separated by white space. eCAP services support
+#	the following name=value options:
+#
+#	bypass=on|off|1|0
+#		If set to 'on' or '1', the eCAP service is treated as optional.
+#		If the service cannot be reached or malfunctions, Squid will try
+#		to ignore any errors and process the message as if the service
 #		was not enabled. No all eCAP errors can be bypassed.
-#		If set to 0, the eCAP service is treated as essential and all
-#		eCAP errors will result in an error page returned to the
+#		If set to 'off' or '0', the eCAP service is treated as essential
+#		and all eCAP errors will result in an error page returned to the
 #		HTTP client.
-#	service_url = ecap://vendor/service_name?custom&cgi=style&parameters=optional
+#
+#                Bypass is off by default: services are treated as essential.
+#
+#	routing=on|off|1|0
+#		If set to 'on' or '1', the eCAP service is allowed to
+#		dynamically change the current message adaptation plan by
+#		returning a chain of services to be used next.
+#
+#		Dynamic adaptation plan may cross or cover multiple supported
+#		vectoring points in their natural processing order.
+#
+#		Routing is not allowed by default.
+#
+#	Older ecap_service format without optional named parameters is
+#	deprecated but supported for backward compatibility.
+#
 #
 #Example:
-#ecap_service service_1 reqmod_precache 0 ecap://filters-R-us/leakDetector?on_error=block
-#ecap_service service_2 respmod_precache 1 icap://filters-R-us/virusFilter?config=/etc/vf.cfg
+#ecap_service s1 reqmod_precache ecap://filters.R.us/leakDetector?on_error=block bypass=off
+#ecap_service s2 respmod_precache ecap://filters.R.us/virusFilter config=/etc/vf.cfg bypass=on
 #Default:
 # none
 
@@ -5247,7 +7348,7 @@ refresh_pattern .		0	20%	4320
 #Example:
 #adaptation_access service_1 allow all
 #Default:
-# none
+# Allow, unless rules exist in squid.conf.
 
 #  TAG: adaptation_service_iteration_limit
 #	Limits the number of iterations allowed when applying adaptation
@@ -5275,8 +7376,14 @@ refresh_pattern .		0	20%	4320
 #
 #	An ICAP REQMOD or RESPMOD transaction may set an entry in the 
 #	shared table by returning an ICAP header field with a name 
-#	specified in adaptation_masterx_shared_names. Squid will store 
-#	and forward that ICAP header field to subsequent ICAP 
+#	specified in adaptation_masterx_shared_names.
+#
+#	An eCAP REQMOD or RESPMOD transaction may set an entry in the
+#	shared table by implementing the libecap::visitEachOption() API
+#	to provide an option with a name specified in
+#	adaptation_masterx_shared_names.
+#
+#	Squid will store and forward the set entry to subsequent adaptation
 #	transactions within the same master transaction scope.
 #
 #	Only one shared entry name is supported at this time.
@@ -5287,6 +7394,43 @@ refresh_pattern .		0	20%	4320
 #Default:
 # none
 
+#  TAG: adaptation_meta
+#	This option allows Squid administrator to add custom ICAP request
+#	headers or eCAP options to Squid ICAP requests or eCAP transactions.
+#	Use it to pass custom authentication tokens and other
+#	transaction-state related meta information to an ICAP/eCAP service.
+#	
+#	The addition of a meta header is ACL-driven:
+#		adaptation_meta name value [!]aclname ...
+#	
+#	Processing for a given header name stops after the first ACL list match.
+#	Thus, it is impossible to add two headers with the same name. If no ACL
+#	lists match for a given header name, no such header is added. For 
+#	example:
+#	
+#		# do not debug transactions except for those that need debugging
+#		adaptation_meta X-Debug 1 needs_debugging
+#	
+#		# log all transactions except for those that must remain secret
+#		adaptation_meta X-Log 1 !keep_secret
+#	
+#		# mark transactions from users in the "G 1" group
+#		adaptation_meta X-Authenticated-Groups "G 1" authed_as_G1
+#	
+#	The "value" parameter may be a regular squid.conf token or a "double
+#	quoted string". Within the quoted string, use backslash (\) to escape
+#	any character, which is currently only useful for escaping backslashes
+#	and double quotes. For example,
+#	    "this string has one backslash (\\) and two \"quotes\""
+#
+#	Used adaptation_meta header values may be logged via %note
+#	logformat code. If multiple adaptation_meta headers with the same name
+#	are used during master transaction lifetime, the header values are
+#	logged in the order they were used and duplicate values are ignored
+#	(only the first repeated value will be logged).
+#Default:
+# none
+
 #  TAG: icap_retry
 #	This ACL determines which retriable ICAP transactions are
 #	retried. Transactions that received a complete ICAP response
@@ -5303,8 +7447,7 @@ refresh_pattern .		0	20%	4320
 # icap_retry deny all
 
 #  TAG: icap_retry_limit
-#	Limits the number of retries allowed. When set to zero (default),
-#	no retries are allowed.
+#	Limits the number of retries allowed.
 #
 #	Communication errors due to persistent connection race
 #	conditions are unavoidable, automatically retried, and do not
@@ -5312,7 +7455,7 @@ refresh_pattern .		0	20%	4320
 #
 #	See also: icap_retry
 #Default:
-# icap_retry_limit 0
+# No retries are allowed.
 
 # DNS OPTIONS
 # -----------------------------------------------------------------------------
@@ -5332,31 +7475,9 @@ refresh_pattern .		0	20%	4320
 #Default:
 # allow_underscore on
 
-#  TAG: cache_dns_program
-# Note: This option is only available if Squid is rebuilt with the
-#       --disable-internal-dns option
-#
-#	Specify the location of the executable for dnslookup process.
-#Default:
-# cache_dns_program /usr/lib/squid/dnsserver
-
-#  TAG: dns_children
-# Note: This option is only available if Squid is rebuilt with the
-#       --disable-internal-dns option
-#
-#	The number of processes spawn to service DNS name lookups.
-#	For heavily loaded caches on large servers, you should
-#	probably increase this value to at least 10.  The maximum
-#	is 32.  The default is 5.
-#
-#	You must have at least one dnsserver process.
-#Default:
-# dns_children 5
-
 #  TAG: dns_retransmit_interval
 #	Initial retransmit interval for DNS queries. The interval is
 #	doubled each time all configured DNS servers have been tried.
-#
 #Default:
 # dns_retransmit_interval 5 seconds
 
@@ -5365,7 +7486,31 @@ refresh_pattern .		0	20%	4320
 #	within this time all DNS servers for the queried domain
 #	are assumed to be unavailable.
 #Default:
-# dns_timeout 2 minutes
+# dns_timeout 30 seconds
+
+#  TAG: dns_packet_max
+#	Maximum number of bytes packet size to advertise via EDNS.
+#	Set to "none" to disable EDNS large packet support.
+#	
+#	For legacy reasons DNS UDP replies will default to 512 bytes which
+#	is too small for many responses. EDNS provides a means for Squid to
+#	negotiate receiving larger responses back immediately without having
+#	to failover with repeat requests. Responses larger than this limit
+#	will retain the old behaviour of failover to TCP DNS.
+#	
+#	Squid has no real fixed limit internally, but allowing packet sizes
+#	over 1500 bytes requires network jumbogram support and is usually not
+#	necessary.
+#	
+#	WARNING: The RFC also indicates that some older resolvers will reply
+#	with failure of the whole request if the extension is added. Some
+#	resolvers have already been identified which will reply with mangled
+#	EDNS response on occasion. Usually in response to many-KB jumbogram
+#	sizes being advertised by Squid.
+#	Squid will currently treat these both as an unable-to-resolve domain
+#	even if it would be resolvable without EDNS.
+#Default:
+# EDNS disabled
 
 #  TAG: dns_defnames	on|off
 #	Normally the RES_DEFNAMES resolver option is disabled
@@ -5373,12 +7518,21 @@ refresh_pattern .		0	20%	4320
 #	from interpreting single-component hostnames locally.  To allow
 #	Squid to handle single-component names, enable this option.
 #Default:
-# dns_defnames off
+# Search for single-label domain names is disabled.
+
+#  TAG: dns_multicast_local	on|off
+#	When set to on, Squid sends multicast DNS lookups on the local
+#	network for domains ending in .local and .arpa.
+#	This enables local servers and devices to be contacted in an
+#	ad-hoc or zero-configuration network environment.
+#Default:
+# Search for .local and .arpa names is disabled.
 
 #  TAG: dns_nameservers
 #	Use this if you want to specify a list of DNS name servers
 #	(IP addresses) to use instead of those given in your
 #	/etc/resolv.conf file.
+#
 #	On Windows platforms, if no value is specified here or in
 #	the /etc/resolv.conf file, the list of DNS name servers are
 #	taken from the Windows registry, both static and dynamic DHCP
@@ -5386,7 +7540,7 @@ refresh_pattern .		0	20%	4320
 #
 #	Example: dns_nameservers 10.0.0.1 192.172.0.4
 #Default:
-# none
+# Use operating system definitions
 
 #  TAG: hosts_file
 #	Location of the host-local IP name-address associations
@@ -5425,7 +7579,7 @@ refresh_pattern .		0	20%	4320
 #Example:
 # append_domain .yourdomain.com
 #Default:
-# none
+# Use operating system definitions
 
 #  TAG: ignore_unknown_nameservers
 #	By default Squid checks that DNS responses are received
@@ -5436,23 +7590,6 @@ refresh_pattern .		0	20%	4320
 #Default:
 # ignore_unknown_nameservers on
 
-#  TAG: dns_v4_fallback
-#	Standard practice with DNS is to lookup either A or AAAA records
-#	and use the results if it succeeds. Only looking up the other if
-#	the first attempt fails or otherwise produces no results.
-#
-#	That policy however will cause squid to produce error pages for some
-#	servers that advertise AAAA but are unreachable over IPv6.
-#
-#	If this is ON  squid will always lookup both AAAA and A, using both.
-#	If this is OFF squid will lookup AAAA and only try A if none found.
-#
-#	WARNING: There are some possibly unwanted side-effects with this on:
-#		*) Doubles the load placed by squid on the DNS network.
-#		*) May negatively impact connection delay times.
-#Default:
-# dns_v4_fallback on
-
 #  TAG: dns_v4_first
 #	With the IPv6 Internet being as fast or faster than IPv4 Internet
 #	for most networks Squid prefers to contact websites over IPv6.
@@ -5464,11 +7601,12 @@ refresh_pattern .		0	20%	4320
 #	WARNING:
 #	  This option will restrict the situations under which IPv6
 #	  connectivity is used (and tested), potentially hiding network
-#	  problem swhich would otherwise be detected and warned about.
+#	  problems which would otherwise be detected and warned about.
 #Default:
 # dns_v4_first off
 
 #  TAG: ipcache_size	(number of entries)
+#	Maximum number of DNS IP cache entries.
 #Default:
 # ipcache_size 1024
 
@@ -5489,6 +7627,15 @@ refresh_pattern .		0	20%	4320
 # MISCELLANEOUS
 # -----------------------------------------------------------------------------
 
+#  TAG: configuration_includes_quoted_values	on|off
+#	If set, Squid will recognize each "quoted string" after a configuration
+#	directive as a single parameter. The quotes are stripped before the
+#	parameter value is interpreted or used.
+#	See "Values with spaces, quotes, and other special characters"
+#	section for more details.
+#Default:
+# configuration_includes_quoted_values off
+
 #  TAG: memory_pools	on|off
 #	If set, Squid will keep pools of allocated (but unused) memory
 #	available for future use.  If memory is a premium on your
@@ -5539,7 +7686,7 @@ refresh_pattern .		0	20%	4320
 #	X-Forwarded-For header.
 #
 #	If set to "truncate", Squid will remove all existing
-#	X-Forwarded-For entries, and place itself as the sole entry.
+#	X-Forwarded-For entries, and place the client IP as the sole entry.
 #Default:
 # forwarded_for on
 
@@ -5602,7 +7749,7 @@ refresh_pattern .		0	20%	4320
 # cachemgr_passwd lesssssssecret info stats/objects
 # cachemgr_passwd disable all
 #Default:
-# none
+# No password. Actions which require password are denied.
 
 #  TAG: client_db	on|off
 #	If you want to disable collecting per-client statistics,
@@ -5633,19 +7780,22 @@ refresh_pattern .		0	20%	4320
 #Default:
 # reload_into_ims off
 
-#  TAG: maximum_single_addr_tries
-#	This sets the maximum number of connection attempts for a
-#	host that only has one address (for multiple-address hosts,
-#	each address is tried once).
+#  TAG: connect_retries
+#	This sets the maximum number of connection attempts made for each
+#	TCP connection. The connect_retries attempts must all still
+#	complete within the connection timeout period.
 #
-#	The default value is one attempt, the (not recommended)
-#	maximum is 255 tries.  A warning message will be generated
-#	if it is set to a value greater than ten.
+#	The default is not to re-try if the first connection attempt fails.
+#	The (not recommended) maximum is 10 tries.
 #
-#	Note: This is in addition to the request re-forwarding which
-#	takes place if Squid fails to get a satisfying response.
+#	A warning message will be generated if it is set to a too-high
+#	value and the configured value will be over-ridden.
+#
+#	Note: These re-tries are in addition to forward_max_tries
+#	which limit how many different addresses may be tried to find
+#	a useful server.
 #Default:
-# maximum_single_addr_tries 1
+# Do not retry failed connections.
 
 #  TAG: retry_on_error
 #	If set to ON Squid will automatically retry requests when
@@ -5678,20 +7828,32 @@ refresh_pattern .		0	20%	4320
 #	URI.  Options:
 #
 #	strip:  The whitespace characters are stripped out of the URL.
-#		This is the behavior recommended by RFC2396.
+#		This is the behavior recommended by RFC2396 and RFC3986
+#		for tolerant handling of generic URI.
+#		NOTE: This is one difference between generic URI and HTTP URLs.
+#
 #	deny:   The request is denied.  The user receives an "Invalid
 #		Request" message.
+#		This is the behaviour recommended by RFC2616 for safe
+#		handling of HTTP request URL.
+#
 #	allow:  The request is allowed and the URI is not changed.  The
 #		whitespace characters remain in the URI.  Note the
 #		whitespace is passed to redirector processes if they
 #		are in use.
+#		Note this may be considered a violation of RFC2616
+#		request parsing where whitespace is prohibited in the
+#		URL field.
+#
 #	encode:	The request is allowed and the whitespace characters are
-#		encoded according to RFC1738.  This could be considered
-#		a violation of the HTTP/1.1
-#		RFC because proxies are not allowed to rewrite URI's.
+#		encoded according to RFC1738.
+#
 #	chop:	The request is allowed and the URI is chopped at the
-#		first whitespace.  This might also be considered a
-#		violation.
+#		first whitespace.
+#
+#
+#	NOTE the current Squid implementation of encode and chop violates
+#	RFC2616 by not using a 301 redirect after altering the URL.
 #Default:
 # uri_whitespace strip
 
@@ -5718,23 +7880,28 @@ refresh_pattern .		0	20%	4320
 # balance_on_multiple_ip off
 
 #  TAG: pipeline_prefetch
-#	To boost the performance of pipelined requests to closer
-#	match that of a non-proxied environment Squid can try to fetch
-#	up to two requests in parallel from a pipeline.
-#
-#	Defaults to off for bandwidth management and access logging
+#	HTTP clients may send a pipeline of 1+N requests to Squid using a
+#	single connection, without waiting for Squid to respond to the first
+#	of those requests. This option limits the number of concurrent
+#	requests Squid will try to handle in parallel. If set to N, Squid
+#	will try to receive and process up to 1+N requests on the same
+#	connection concurrently.
+#
+#	Defaults to 0 (off) for bandwidth management and access logging
 #	reasons.
 #
+#	NOTE: pipelining requires persistent connections to clients.
+#
 #	WARNING: pipelining breaks NTLM and Negotiate/Kerberos authentication.
 #Default:
-# pipeline_prefetch off
+# Do not pre-parse pipelined requests.
 
 #  TAG: high_response_time_warning	(msec)
 #	If the one-minute median response time exceeds this value,
 #	Squid prints a WARNING with debug level 0 to get the
 #	administrators attention.  The value is in milliseconds.
 #Default:
-# high_response_time_warning 0
+# disabled.
 
 #  TAG: high_page_fault_warning
 #	If the one-minute average page fault rate exceeds this
@@ -5742,14 +7909,17 @@ refresh_pattern .		0	20%	4320
 #	the administrators attention.  The value is in page faults
 #	per second.
 #Default:
-# high_page_fault_warning 0
+# disabled.
 
 #  TAG: high_memory_warning
-#	If the memory usage (as determined by mallinfo) exceeds
-#	this amount, Squid prints a WARNING with debug level 0 to get
+# Note: This option is only available if Squid is rebuilt with the
+#       GNU Malloc with mstats()
+#
+#	If the memory usage (as determined by gnumalloc, if available and used)
+#	exceeds	this amount, Squid prints a WARNING with debug level 0 to get
 #	the administrators attention.
 #Default:
-# high_memory_warning 0 KB
+# disabled.
 
 #  TAG: sleep_after_fork	(microseconds)
 #	When this is set to a non-zero value, the main Squid process
@@ -5766,6 +7936,9 @@ refresh_pattern .		0	20%	4320
 # sleep_after_fork 0
 
 #  TAG: windows_ipaddrchangemonitor	on|off
+# Note: This option is only available if Squid is rebuilt with the
+#       MS Windows
+#
 #	On Windows Squid by default will monitor IP address changes and will 
 #	reconfigure itself after any detected event. This is very useful for
 #	proxies connected to internet with dial-up interfaces.
@@ -5775,13 +7948,19 @@ refresh_pattern .		0	20%	4320
 #Default:
 # windows_ipaddrchangemonitor on
 
+#  TAG: eui_lookup
+#	Whether to lookup the EUI or MAC address of a connected client.
+#Default:
+# eui_lookup on
+
 #  TAG: max_filedescriptors
-#	The maximum number of filedescriptors supported.
+#	Reduce the maximum number of filedescriptors supported below
+#	the usual operating system defaults.
 #
-#	The default "0" means Squid inherits the current ulimit setting.
+#	Remove from squid.conf to inherit the current ulimit setting.
 #
 #	Note: Changing this requires a restart of Squid. Also
-#	not all comm loops supports large values.
+#	not all I/O types supports large values (eg on Windows).
 #Default:
-# max_filedescriptors 0
+# Use operating system limits set by ulimit.