+ If you don't know what any of this means, there probably is no reason to
+ change this one, since the default is already very restrictive.
+
+Example usages:
+
+ +limit-connect{443} # This is the default and need not be specified.
+ +limit-connect{80,443} # Ports 80 and 443 are OK.
+ +limit-connect{-3, 7, 20-100, 500-} # Ports less than 3, 7, 20 to 100 and above 500 are OK.
+ +limit-connect{-} # All ports are OK (gaping security hole!)
+
+
+-------------------------------------------------------------------------------
+
+8.5.16. prevent-compression
+
+Typical use:
+
+ Ensure that servers send the content uncompressed, so it can be passed
+ through filters
+
+Effect:
+
+ Adds a header to the request that asks for uncompressed transfer.
+
+Type:
+
+ Boolean.
+
+Parameter:
+
+ N/A
+
+Notes:
+
+ More and more websites send their content compressed by default, which is
+ generally a good idea and saves bandwidth. But for the filter,
+ deanimate-gifs and kill-popups actions to work, Privoxy needs access to the
+ uncompressed data. Unfortunately, Privoxy can't yet(!) uncompress, filter,
+ and re-compress the content on the fly. So if you want to ensure that all
+ websites, including those that normally compress, can be filtered, you need
+ to use this action.
+
+ This will slow down transfers from those websites, though. If you use any
+ of the above-mentioned actions, you will typically want to use
+ prevent-compression in conjunction with them.
+
+ Note that some (rare) ill-configured sites don't handle requests for
+ uncompressed documents correctly (they send an empty document body). If you
+ use prevent-compression per default, you'll have to add exceptions for
+ those sites. See the example for how to do that.
+
+Example usage (sections):
+
+ # Set default:
+ #
+ {+prevent-compression}
+ / # Match all sites
+
+ # Make exceptions for ill sites:
+ #
+ {-prevent-compression}
+ www.debianhelp.org
+ www.pclinuxonline.com
+
+
+-------------------------------------------------------------------------------
+
+8.5.17. send-vanilla-wafer
+
+Typical use:
+
+ Feed log analysis scripts with useless data.
+
+Effect:
+
+ Sends a cookie with each request stating that you do not accept any
+ copyright on cookies sent to you, and asking the site operator not to track
+ you.
+
+Type:
+
+ Boolean.
+
+Parameter:
+
+ N/A
+
+Notes:
+
+ The vanilla wafer is a (relatively) unique header and could conceivably be
+ used to track you.
+
+ This action is rarely used and not enabled in the default configuration.
+
+Example usage:
+
+ +send-vanilla-wafer
+
+
+-------------------------------------------------------------------------------
+
+8.5.18. send-wafer
+
+Typical use:
+
+ Send custom cookies or feed log analysis scripts with even more useless
+ data.
+
+Effect:
+
+ Sends a custom, user-defined cookie with each request.
+
+Type:
+
+ Multi-value.
+
+Parameter:
+
+ A string of the form "name=value".
+
+Notes:
+
+ Being multi-valued, multiple instances of this action can apply to the same
+ request, resulting in multiple cookies being sent.
+
+ This action is rarely used and not enabled in the default configuration.
+
+Example usage (section):
+
+ {+send-wafer{UsingPrivoxy=true}}
+ my-internal-testing-server.void
+
+
+-------------------------------------------------------------------------------
+
+8.5.19. session-cookies-only
+
+Typical use:
+
+ Allow only temporary "session" cookies (for the current browser session
+ only).
+
+Effect:
+
+ Deletes the "expires" field from "Set-Cookie:" server headers. Most
+ browsers will not store such cookies permanently and forget them in between
+ sessions.
+
+Type:
+
+ Boolean.
+
+Parameter:
+
+ N/A
+
+Notes:
+
+ This is less strict than crunch-incoming-cookies / crunch-outgoing-cookies
+ and allows you to browse websites that insist or rely on setting cookies,
+ without compromising your privacy too badly.
+
+ Most browsers will not permanently store cookies that have been processed
+ by session-cookies-only and will forget about them between sessions. This
+ makes profiling cookies useless, but won't break sites which require
+ cookies so that you can log in for transactions. This is generally turned
+ on for all sites, and is the recommended setting.
+
+ It makes no sense at all to use session-cookies-only together with
+ crunch-incoming-cookies or crunch-outgoing-cookies. If you do, cookies will
+ be plainly killed.
+
+ Note that it is up to the browser how it handles such cookies without an
+ "expires" field. If you use an exotic browser, you might want to try it out
+ to be sure.
+
+ This setting also has no effect on cookies that may have been stored
+ previously by the browser before starting Privoxy. These would have to be
+ removed manually.
+
+ Privoxy also uses the content-cookies filter to block some types of
+ cookies. Content cookies are not effected by session-cookies-only.
+
+Example usage:
+
+ +session-cookies-only
+
+
+-------------------------------------------------------------------------------
+
+8.5.20. set-image-blocker
+
+Typical use:
+
+ Choose the replacement for blocked images
+
+Effect:
+
+ This action alone doesn't do anything noticeable. If both block and
+ handle-as-image also apply, i.e. if the request is to be blocked as an
+ image, then the parameter of this action decides what will be sent as a
+ replacement.
+
+Type:
+
+ Parameterized.
+
+Parameter:
+
+ + "pattern" to send a built-in checkerboard pattern image. The image is
+ visually decent, scales very well, and makes it obvious where banners
+ were busted.
+
+ + "blank" to send a built-in transparent image. This makes banners
+ disappear completely, but makes it hard to detect where Privoxy has
+ blocked images on a given page and complicates troubleshooting if
+ Privoxy has blocked innocent images, like navigation icons.
+
+ + "target-url" to send a redirect to target-url. You can redirect to any
+ image anywhere, even in your local filesystem (via "file:///" URL).
+
+ A good application of redirects is to use special Privoxy-built-in
+ URLs, which send the built-in images, as target-url. This has the same
+ visual effect as specifying "blank" or "pattern" in the first place,
+ but enables your browser to cache the replacement image, instead of
+ requesting it over and over again.
+
+Notes:
+
+ The URLs for the built-in images are "http://config.privoxy.org/
+ send-banner?type=type", where type is either "blank" or "pattern".
+
+ There is a third (advanced) type, called "auto". It is NOT to be used in
+ set-image-blocker, but meant for use from filters. Auto will select the
+ type of image that would have applied to the referring page, had it been an
+ image.
+
+Example usage:
+
+ Built-in pattern:
+
+ +set-image-blocker{pattern}
+
+
+ Redirect to the BSD devil:
+
+ +set-image-blocker{http://www.freebsd.org/gifs/dae_up3.gif}
+
+
+ Redirect to the built-in pattern for better caching:
+
+ +set-image-blocker{http://config.privoxy.org/send-banner?type=pattern}
+
+
+-------------------------------------------------------------------------------
+
+8.5.21. Summary
+
+Note that many of these actions have the potential to cause a page to
+misbehave, possibly even not to display at all. There are many ways a site
+designer may choose to design his site, and what HTTP header content, and other
+criteria, he may depend on. There is no way to have hard and fast rules for all
+sites. See the Appendix for a brief example on troubleshooting actions.
+
+-------------------------------------------------------------------------------
+
+8.6. Aliases
+
+Custom "actions", known to Privoxy as "aliases", can be defined by combining
+other actions. These can in turn be invoked just like the built-in actions.
+Currently, an alias name can contain any character except space, tab, "=", "{"
+and "}", but we strongly recommend that you only use "a" to "z", "0" to "9",
+"+", and "-". Alias names are not case sensitive, and are not required to start
+with a "+" or "-" sign, since they are merely textually expanded.
+
+Aliases can be used throughout the actions file, but they must be defined in a
+special section at the top of the file! And there can only be one such section
+per actions file. Each actions file may have its own alias section, and the
+aliases defined in it are only visible within that file.
+
+There are two main reasons to use aliases: One is to save typing for frequently
+used combinations of actions, the other one is a gain in flexibility: If you
+decide once how you want to handle shops by defining an alias called "shop",
+you can later change your policy on shops in one place, and your changes will
+take effect everywhere in the actions file where the "shop" alias is used.
+Calling aliases by their purpose also makes your actions files more readable.
+
+Currently, there is one big drawback to using aliases, though: Privoxy's
+built-in web-based action file editor honors aliases when reading the actions
+files, but it expands them before writing. So the effects of your aliases are
+of course preserved, but the aliases themselves are lost when you edit sections
+that use aliases with it. This is likely to change in future versions of
+Privoxy.
+
+Now let's define some aliases...
+
+ # Useful custom aliases we can use later.
+ #
+ # Note the (required!) section header line and that this section
+ # must be at the top of the actions file!
+ #
+ {{alias}}
+
+ # These aliases just save typing later:
+ # (Note that some already use other aliases!)
+ #
+ +crunch-all-cookies = +crunch-incoming-cookies +crunch-outgoing-cookies
+ -crunch-all-cookies = -crunch-incoming-cookies -crunch-outgoing-cookies
+ block-as-image = +block +handle-as-image
+ mercy-for-cookies = -crunch-all-cookies -session-cookies-only -filter{content-cookies}
+
+ # These aliases define combinations of actions
+ # that are useful for certain types of sites:
+ #
+ fragile = -block -filter -crunch-all-cookies -fast-redirects -hide-referrer -kill-popups
+ shop = -crunch-all-cookies -filter{all-popups} -kill-popups
+
+ # Short names for other aliases, for really lazy people ;-)
+ #
+ c0 = +crunch-all-cookies
+ c1 = -crunch-all-cookies
+
+
+...and put them to use. These sections would appear in the lower part of an
+actions file and define exceptions to the default actions (as specified further
+up for the "/" pattern):
+
+ # These sites are either very complex or very keen on
+ # user data and require minimal interference to work:
+ #
+ {fragile}
+ .office.microsoft.com
+ .windowsupdate.microsoft.com
+ .nytimes.com
+
+ # Shopping sites:
+ # Allow cookies (for setting and retrieving your customer data)
+ #
+ {shop}
+ .quietpc.com
+ .worldpay.com # for quietpc.com
+ .scan.co.uk
+
+ # These shops require pop-ups:
+ #
+ {shop -kill-popups -filter{all-popups}}
+ .dabs.com
+ .overclockers.co.uk
+
+
+Aliases like "shop" and "fragile" are often used for "problem" sites that
+require some actions to be disabled in order to function properly.
+
+-------------------------------------------------------------------------------
+
+8.7. Actions Files Tutorial
+
+The above chapters have shown which actions files there are and how they are
+organized, how actions are specified and applied to URLs, how patterns work,
+and how to define and use aliases. Now, let's look at an example default.action
+and user.action file and see how all these pieces come together:
+
+-------------------------------------------------------------------------------
+
+8.7.1. default.action
+
+Every config file should start with a short comment stating its purpose:
+
+# Sample default.action file <developers@privoxy.org>
+
+
+Then, since this is the default.action file, the first section is a special
+section for internal use that you needn't change or worry about:
+
+##########################################################################
+# Settings -- Don't change! For internal Privoxy use ONLY.
+##########################################################################
+
+{{settings}}
+for-privoxy-version=3.0
+
+
+After that comes the (optional) alias section. We'll use the example section
+from the above chapter on aliases, that also explains why and how aliases are
+used:
+
+##########################################################################
+# Aliases
+##########################################################################
+{{alias}}
+
+ # These aliases just save typing later:
+ # (Note that some already use other aliases!)
+ #
+ +crunch-all-cookies = +crunch-incoming-cookies +crunch-outgoing-cookies
+ -crunch-all-cookies = -crunch-incoming-cookies -crunch-outgoing-cookies
+ block-as-image = +block +handle-as-image
+ mercy-for-cookies = -crunch-all-cookies -session-cookies-only -filter{content-cookies}
+
+ # These aliases define combinations of actions
+ # that are useful for certain types of sites:
+ #
+ fragile = -block -filter -crunch-all-cookies -fast-redirects -hide-referrer -kill-popups
+ shop = -crunch-all-cookies -filter{all-popups} -kill-popups
+
+
+Now come the regular sections, i.e. sets of actions, accompanied by URL
+patterns to which they apply. Remember all actions are disabled when matching
+starts, so we have to explicitly enable the ones we want.
+
+The first regular section is probably the most important. It has only one
+pattern, "/", but this pattern matches all URLs. Therefore, the set of actions
+used in this "default" section will be applied to all requests as a start. It
+can be partly or wholly overridden by later matches further down this file, or
+in user.action, but it will still be largely responsible for your overall
+browsing experience.
+
+Again, at the start of matching, all actions are disabled, so there is no real
+need to disable any actions here, but we will do that nonetheless, to have a
+complete listing for your reference. (Remember: a "+" preceding the action name
+enables the action, a "-" disables!). Also note how this long line has been
+made more readable by splitting it into multiple lines with line continuation.
+
+##########################################################################
+# "Defaults" section:
+##########################################################################
+ { \
+ -add-header \
+ -block \
+ -crunch-incoming-cookies \
+ -crunch-outgoing-cookies \
+ +deanimate-gifs \
+ -downgrade-http-version \
+ +fast-redirects \
+ +filter{js-annoyances} \
+ -filter{js-events} \
+ +filter{html-annoyances} \
+ -filter{content-cookies} \
+ +filter{refresh-tags} \
+ +filter{unsolicited-popups} \
+ -filter{all-popups} \
+ +filter{img-reorder} \
+ +filter{banners-by-size} \
+ -filter{banners-by-link} \
+ +filter{webbugs} \
+ -filter{tiny-textforms} \
+ +filter{jumping-windows} \
+ -filter{frameset-borders} \
+ -filter{demoronizer} \
+ -filter{shockwave-flash} \
+ -filter{quicktime-kioskmode} \
+ -filter{fun} \
+ -filter{crude-parental} \
+ +filter{ie-exploits} \
+ -handle-as-image \
+ +hide-forwarded-for-headers \
+ +hide-from-header{block} \
+ +hide-referrer{forge} \
+ -hide-user-agent \
+ -kill-popups \
+ -limit-connect \
+ +prevent-compression \
+ -send-vanilla-wafer \
+ -send-wafer \
+ +session-cookies-only \
+ +set-image-blocker{pattern} \
+ }
+ / # forward slash will match *all* potential URL patterns.
+
+
+The default behavior is now set. Note that some actions, like not hiding the
+user agent, are part of a "general policy" that applies universally and won't
+get any exceptions defined later. Other choices, like not blocking (which is
+understandably the default!) need exceptions, i.e. we need to specify
+explicitly what we want to block in later sections.
+
+The first of our specialized sections is concerned with "fragile" sites, i.e.
+sites that require minimum interference, because they are either very complex
+or very keen on tracking you (and have mechanisms in place that make them
+unusable for people who avoid being tracked). We will simply use our
+pre-defined fragile alias instead of stating the list of actions explicitly:
+
+##########################################################################
+# Exceptions for sites that'll break under the default action set:
+##########################################################################
+
+# "Fragile" Use a minimum set of actions for these sites (see alias above):
+#
+{ fragile }
+.office.microsoft.com # surprise, surprise!
+.windowsupdate.microsoft.com
+
+
+Shopping sites are not as fragile, but they typically require cookies to log
+in, and pop-up windows for shopping carts or item details. Again, we'll use a
+pre-defined alias:
+
+# Shopping sites:
+#
+{ shop }
+.quietpc.com
+.worldpay.com # for quietpc.com
+.jungle.com
+.scan.co.uk
+
+
+The fast-redirects action, which we enabled per default above, breaks some
+sites. So disable it for popular sites where we know it misbehaves:
+
+{ -fast-redirects }
+login.yahoo.com
+edit.*.yahoo.com
+.google.com
+.altavista.com/.*(like|url|link):http
+.altavista.com/trans.*urltext=http
+.nytimes.com
+
+
+It is important that Privoxy knows which URLs belong to images, so that if they
+are to be blocked, a substitute image can be sent, rather than an HTML page.
+Contacting the remote site to find out is not an option, since it would destroy
+the loading time advantage of banner blocking, and it would feed the
+advertisers (in terms of money and information). We can mark any URL as an
+image with the handle-as-image action, and marking all URLs that end in a known
+image file extension is a good start:
+
+##########################################################################
+# Images:
+##########################################################################
+
+# Define which file types will be treated as images, in case they get
+# blocked further down this file:
+#
+{ +handle-as-image }
+/.*\.(gif|jpe?g|png|bmp|ico)$
+
+
+And then there are known banner sources. They often use scripts to generate the
+banners, so it won't be visible from the URL that the request is for an image.
+Hence we block them and mark them as images in one go, with the help of our
+block-as-image alias defined above. (We could of course just as well use +block
++handle-as-image here.) Remember that the type of the replacement image is
+chosen by the set-image-blocker action. Since all URLs have matched the default
+section with its +set-image-blocker{pattern} action before, it still applies
+and needn't be repeated:
+
+# Known ad generators:
+#
+{ block-as-image }
+ar.atwola.com
+.ad.doubleclick.net
+.ad.*.doubleclick.net
+.a.yimg.com/(?:(?!/i/).)*$
+.a[0-9].yimg.com/(?:(?!/i/).)*$
+bs*.gsanet.com
+bs*.einets.com
+.qkimg.net
+
+
+One of the most important jobs of Privoxy is to block banners. A huge bunch of
+them are already "blocked" by the filter{banners-by-size} action, which we
+enabled above, and which deletes the references to banner images from the pages
+while they are loaded, so the browser doesn't request them anymore, and hence
+they don't need to be blocked here. But this naturally doesn't catch all
+banners, and some people choose not to use filters, so we need a comprehensive
+list of patterns for banner URLs here, and apply the block action to them.
+
+First comes a bunch of generic patterns, which do most of the work, by matching
+typical domain and path name components of banners. Then comes a list of
+individual patterns for specific sites, which is omitted here to keep the
+example short:
+
+##########################################################################
+# Block these fine banners:
+##########################################################################
+{ +block }
+
+# Generic patterns:
+#
+ad*.
+.*ads.
+banner?.
+count*.
+/.*count(er)?\.(pl|cgi|exe|dll|asp|php[34]?)
+/(?:.*/)?(publicite|werbung|rekla(ma|me|am)|annonse|maino(kset|nta|s)?)/
+
+# Site-specific patterns (abbreviated):
+#
+.hitbox.com
+
+
+You wouldn't believe how many advertisers actually call their banner servers
+ads.company.com, or call the directory in which the banners are stored simply
+"banners". So the above generic patterns are surprisingly effective.
+
+But being very generic, they necessarily also catch URLs that we don't want to
+block. The pattern .*ads. e.g. catches "nasty-ads.nasty-corp.com" as intended,
+but also "downloads.sourcefroge.net" or "adsl.some-provider.net." So here come
+some well-known exceptions to the +block section above.
+
+Note that these are exceptions to exceptions from the default! Consider the URL
+"downloads.sourcefroge.net": Initially, all actions are deactivated, so it
+wouldn't get blocked. Then comes the defaults section, which matches the URL,
+but just deactivates the block action once again. Then it matches .*ads., an
+exception to the general non-blocking policy, and suddenly +block applies. And
+now, it'll match .*loads., where -block applies, so (unless it matches again
+further down) it ends up with no block action applying.
+
+##########################################################################
+# Save some innocent victims of the above generic block patterns:
+##########################################################################
+
+# By domain:
+#
+{ -block }
+adv[io]*. # (for advogato.org and advice.*)
+adsl. # (has nothing to do with ads)
+ad[ud]*. # (adult.* and add.*)
+.edu # (universities don't host banners (yet!))
+.*loads. # (downloads, uploads etc)
+
+# By path:
+#
+/.*loads/
+
+# Site-specific:
+#
+www.globalintersec.com/adv # (adv = advanced)
+www.ugu.com/sui/ugu/adv
+
+
+Filtering source code can have nasty side effects, so make an exception for our
+friends at sourceforge.net, and all paths with "cvs" in them. Note that -filter
+disables all filters in one fell swoop!
+
+# Don't filter code!
+#
+{ -filter }
+/.*cvs
+.sourceforge.net
+
+
+The actual default.action is of course more comprehensive, but we hope this
+example made clear how it works.
+
+-------------------------------------------------------------------------------
+
+8.7.2. user.action
+
+So far we are painting with a broad brush by setting general policies, which
+would be a reasonable starting point for many people. Now, you might want to be
+more specific and have customized rules that are more suitable to your personal
+habits and preferences. These would be for narrowly defined situations like
+your ISP or your bank, and should be placed in user.action, which is parsed
+after all other actions files and hence has the last word, over-riding any
+previously defined actions. user.action is also a safe place for your personal
+settings, since default.action is actively maintained by the Privoxy developers
+and you'll probably want to install updated versions from time to time.
+
+So let's look at a few examples of things that one might typically do in
+user.action:
+
+# My user.action file. <fred@foobar.com>
+
+
+As aliases are local to the actions file that they are defined in, you can't
+use the ones from default.action, unless you repeat them here:
+
+# Aliases are local to the file they are defined in.
+# (Re-)define aliases for this file:
+#
+{{alias}}
+#
+# These aliases just save typing later, and the alias names should
+# be self explanatory.
+#
++crunch-all-cookies = +crunch-incoming-cookies +crunch-outgoing-cookies
+-crunch-all-cookies = -crunch-incoming-cookies -crunch-outgoing-cookies
+ allow-all-cookies = -crunch-all-cookies -session-cookies-only
+ allow-popups = -filter{all-popups} -kill-popups
++block-as-image = +block +handle-as-image
+-block-as-image = -block
+
+# These aliases define combinations of actions that are useful for
+# certain types of sites:
+#
+fragile = -block -crunch-all-cookies -filter -fast-redirects -hide-referrer -kill-popups
+shop = -crunch-all-cookies allow-popups
+
+# Allow ads for selected useful free sites:
+#
+allow-ads = -block -filter{banners-by-size} -filter{banners-by-link}
+
+
+Say you have accounts on some sites that you visit regularly, and you don't
+want to have to log in manually each time. So you'd like to allow persistent
+cookies for these sites. The allow-all-cookies alias defined above does exactly
+that, i.e. it disables crunching of cookies in any direction, and the
+processing of cookies to make them only temporary.
+
+{ allow-all-cookies }
+sourceforge.net
+sunsolve.sun.com
+.slashdot.org
+.yahoo.com
+.msdn.microsoft.com
+.redhat.com
+
+
+Your bank is allergic to some filter, but you don't know which, so you disable
+them all:
+
+{ -filter }
+.your-home-banking-site.com
+
+
+Some file types you may not want to filter for various reasons:
+
+# Technical documentation is likely to contain strings that might
+# erroneously get altered by the JavaScript-oriented filters:
+#
+.tldp.org
+/(.*/)?selfhtml/
+
+# And this stupid host sends streaming video with a wrong MIME type,
+# so that Privoxy thinks it is getting HTML and starts filtering:
+#
+stupid-server.example.com/
+