+<!-- ~~~~~ New section ~~~~~ -->
+<sect3>
+<title>Summary</title>
+<para>
+ 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 <link
+ linkend="ACTIONSANAT">Appendix</link> for a brief example on troubleshooting
+ actions.
+</para>
+</sect3>
+</sect2>
+
+<!-- ~~~~~ New section ~~~~~ -->
+<sect2 id="aliases">
+<title>Aliases</title>
+<para>
+ Custom <quote>actions</quote>, known to <application>Privoxy</application>
+ as <quote>aliases</quote>, 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,
+ <quote>=</quote>,
+ <quote>{</quote> and <quote>}</quote>, but we <emphasis>strongly
+ recommend</emphasis> that you only use <quote>a</quote> to <quote>z</quote>,
+ <quote>0</quote> to <quote>9</quote>, <quote>+</quote>, and <quote>-</quote>.
+ Alias names are not case sensitive, and are not required to start with a
+ <quote>+</quote> or <quote>-</quote> sign, since they are merely textually
+ expanded.
+</para>
+<para>
+ Aliases can be used throughout the actions file, but they <emphasis>must be
+ defined in a special section at the top of the file!</emphasis>
+ 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.
+</para>
+<para>
+ 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
+ <quote>shop</quote>, you can later change your policy on shops in
+ <emphasis>one</emphasis> place, and your changes will take effect everywhere
+ in the actions file where the <quote>shop</quote> alias is used. Calling aliases
+ by their purpose also makes your actions files more readable.
+</para>
+<para>
+ Currently, there is one big drawback to using aliases, though:
+ <application>Privoxy</application>'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 <application>Privoxy</application>.
+</para>
+
+<para>
+ Now let's define some aliases...
+</para>
+
+<para>
+ <screen>
+ # 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
+
+ # These aliases define combinations of actions
+ # that are useful for certain types of sites:
+ #
+ fragile = -block -crunch-all-cookies -filter -fast-redirects -hide-referer -kill-popups
+ shop = -crunch-all-cookies -filter{popups} -kill-popups
+
+ # Short names for other aliases, for really lazy people ;-)
+ #
+ c0 = +crunch-all-cookies
+ c1 = -crunch-all-cookies</screen>
+</para>
+
+<para>
+ ...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 <quote>/</quote> pattern):
+</para>
+
+<para>
+ <screen>
+ # 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{popups}}
+ .dabs.com
+ .overclockers.co.uk</screen>
+</para>
+
+<para>
+ Aliases like <quote>shop</quote> and <quote>fragile</quote> are often used for
+ <quote>problem</quote> sites that require some actions to be disabled
+ in order to function properly.
+</para>
+</sect2>
+
+<!-- ~~~~~ New section ~~~~~ -->
+<sect2 id="act-examples">
+<title>Actions Files Tutorial</title>
+<para>
+ The above chapters have shown <link linkend="actions-file">which actions files
+ there are and how they are organized</link>, how actions are <link
+ linkend="actions">specified</link> and <link linkend="actions-apply">applied
+ to URLs</link>, how <link linkend="af-patterns">patterns</link> work, and how to
+ define and use <link linkend="aliases">aliases</link>. Now, let's look at an
+ example <filename>default.action</filename> and <filename>user.action</filename>
+ file and see how all these pieces come together:
+</para>
+
+<sect3><title>default.action</title>
+
+<para>
+Every config file should start with a short comment stating its purpose:
+</para>
+
+<para>
+ <screen># Sample default.action file <developers@privoxy.org></screen>
+</para>
+
+<para>
+Then, since this is the <filename>default.action</filename> file, the
+first section is a special section for internal use that you needn't
+change or worry about:
+</para>
+
+<para>
+ <screen>
+##########################################################################
+# Settings -- Don't change! For internal Privoxy use ONLY.
+##########################################################################
+
+{{settings}}
+for-privoxy-version=3.0</screen>
+</para>
+
+<para>
+After that comes the (optional) alias section. We'll use the example
+section from the above <link linkend="aliases">chapter on aliases</link>,
+that also explains why and how aliases are used:
+</para>
+
+<para>
+ <screen>
+##########################################################################
+# 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
+
+# These aliases define combinations of actions
+# that are useful for certain types of sites:
+#
+fragile = -block -crunch-all-cookies -filter -fast-redirects -hide-referer -kill-popups
+shop = mercy-for-cookies -filter{popups} -kill-popups</screen>
+</para>
+
+<para>
+ Now come the regular sections, i.e. sets of actions, accompanied
+ by URL patterns to which they apply. Remember <emphasis>all actions
+ are disabled when matching starts</emphasis>, so we have to explicitly
+ enable the ones we want.
+</para>
+
+<para>
+ The first regular section is probably the most important. It has only
+ one pattern, <quote><literal>/</literal></quote>, but this pattern
+ <link linkend="af-patterns">matches all URLs.</link>. Therefore, the
+ set of actions used in this <quote>default</quote> section <emphasis>will
+ be applied to all requests as a start</emphasis>. 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.
+</para>
+
+<para>
+ 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 <quote>+</quote>
+ preceding the action name enables the action, a <quote>-</quote> disables!).
+ Also note how this long line has been made more readable by splitting it into
+ multiple lines with line continuation.
+</para>
+
+<para>
+ <screen>
+##########################################################################
+# "Defaults" section:
+##########################################################################
+ { \
+ -<link linkend="ADD-HEADER">add-header</link> \
+ -<link linkend="BLOCK">block</link> \
+ -<link linkend="CRUNCH-INCOMING-COOKIES">crunch-incoming-cookies</link> \
+ -<link linkend="CRUNCH-OUTGOING-COOKIES">crunch-outgoing-cookies</link> \
+ +<link linkend="DEANIMATE-GIFS">deanimate-gifs</link> \
+ -<link linkend="DOWNGRADE-HTTP-VERSION">downgrade-http-version</link> \
+ +<link linkend="FAST-REDIRECTS">fast-redirects</link> \
+ +<link linkend="FILTER-HTML-ANNOYANCES">filter{html-annoyances}</link> \
+ +<link linkend="FILTER-JS-ANNOYANCES">filter{js-annoyances}</link> \
+ -<link linkend="FILTER-CONTENT-COOKIES">filter{content-cookies}</link> \
+ +<link linkend="FILTER-POPUPS">filter{popups}</link> \
+ +<link linkend="FILTER-WEBBUGS">filter{webbugs}</link> \
+ -<link linkend="FILTER-REFRESH-TAGS">filter{refresh-tags}</link> \
+ -<link linkend="FILTER-FUN">filter{fun}</link> \
+ +<link linkend="FILTER-NIMDA">filter{nimda}</link> \
+ +<link linkend="FILTER-BANNERS-BY-SIZE">filter{banners-by-size}</link> \
+ -<link linkend="FILTER-SHOCKWAVE-FLASH">filter{shockwave-flash}</link> \
+ -<link linkend="FILTER-CRUDE-PARENTAL">filter{crude-parental}</link> \
+ -<link linkend="HANDLE-AS-IMAGE">handle-as-image</link> \
+ +<link linkend="HIDE-FORWARDED-FOR-HEADERS">hide-forwarded-for-headers</link> \
+ +<link linkend="HIDE-FROM-HEADER">hide-from-header{block}</link> \
+ +<link linkend="HIDE-REFERER">hide-referrer{forge}</link> \
+ -<link linkend="HIDE-USER-AGENT">hide-user-agent</link> \
+ -<link linkend="KILL-POPUPS">kill-popups</link> \
+ -<link linkend="LIMIT-CONNECT">limit-connect</link> \
+ +<link linkend="PREVENT-COMPRESSION">prevent-compression</link> \
+ -<link linkend="SEND-VANILLA-WAFER">send-vanilla-wafer</link> \
+ -<link linkend="SEND-WAFER">send-wafer</link> \
+ +<link linkend="SESSION-COOKIES-ONLY">session-cookies-only</link> \
+ +<link linkend="SET-IMAGE-BLOCKER">set-image-blocker{pattern}</link> \
+ }
+ / # forward slash will match *all* potential URL patterns.</screen>
+</para>
+
+<para>
+ The default behavior is now set. Note that some actions, like not hiding
+ the user agent, are part of a <quote>general policy</quote> that applies
+ universally and won't get any exceptions defined later. Other choices,
+ like not blocking (which is <emphasis>understandably</emphasis> the
+ default!) need exceptions, i.e. we need to specify explicitly what we
+ want to block in later sections.
+ We will also want to make exceptions from our general pop-up-killing,
+ and use our defined aliases for that.
+</para>
+
+<para>
+ The first of our specialized sections is concerned with <quote>fragile</quote>
+ 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 <literal>fragile</literal> alias instead of stating the list
+ of actions explicitly:
+</para>
+
+<para>
+ <screen>
+##########################################################################
+# 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</screen>
+</para>
+
+<para>
+ 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:
+</para>
+
+<para>
+ <screen>
+# Shopping sites:
+#
+{ shop }
+.quietpc.com
+.worldpay.com # for quietpc.com
+.jungle.com
+.scan.co.uk</screen>
+</para>
+
+<para>
+ Then, there are sites which rely on pop-up windows (yuck!) to work.
+ Since we made pop-up-killing our default above, we need to make exceptions
+ now. <ulink url="http://www.mozilla.org/">Mozilla</ulink> users, who
+ can turn on smart handling of unwanted pop-ups in their browsers, can
+ safely choose
+ -<literal><link linkend="FILTER-POPUPS">filter{popups}</link></literal> (and
+ -<literal><link linkend="KILL-POPUPS">kill-popups</link></literal>) above
+ and hence don't need this section. Anyway, disabling an already disabled
+ action doesn't hurt, so we'll define our exceptions regardless of what was
+ chosen in the defaults section:
+</para>
+
+<para>
+ <screen>
+# These sites require pop-ups too :(
+#
+{ -<link linkend="KILL-POPUPS">kill-popups</link> -<link linkend="FILTER-POPUPS">filter{popups}</link> }
+.dabs.com
+.overclockers.co.uk
+.deutsche-bank-24.de</screen>
+</para>
+
+<para>
+ The <literal><link linkend="FAST-REDIRECTS">fast-redirects</link></literal>
+ action, which we enabled per default above, breaks some sites. So disable
+ it for popular sites where we know it misbehaves:
+</para>
+
+<para>
+ <screen>
+{ -<link linkend="FAST-REDIRECTS">fast-redirects</link> }
+login.yahoo.com
+edit.*.yahoo.com
+.google.com
+.altavista.com/.*(like|url|link):http
+.altavista.com/trans.*urltext=http
+.nytimes.com</screen>
+</para>
+
+<para>
+ It is important that <application>Privoxy</application> knows which
+ URLs belong to images, so that <emphasis>if</emphasis> 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 <emphasis>and</emphasis>
+ information). We can mark any URL as an image with the <literal><link
+ linkend="handle-as-image">handle-as-image</link></literal> action,
+ and marking all URLs that end in a known image file extension is a
+ good start:
+</para>
+
+<para>
+ <screen>
+##########################################################################
+# Images:
+##########################################################################
+
+# Define which file types will be treated as images, in case they get
+# blocked further down this file:
+#
+{ +<link linkend="HANDLE-AS-IMAGE">handle-as-image</link> }
+/.*\.(gif|jpe?g|png|bmp|ico)$</screen>
+</para>
+
+<para>
+ And then there are known banner sources. They often use scripts to
+ generate the banners, so it won't be visible from the URL that the
+ request is for an image. Hence we block them <emphasis>and</emphasis>
+ mark them as images in one go, with the help of our
+ <literal>block-as-image</literal> alias defined above. (We could of
+ course just as well use <literal>+<link linkend="block">block</link>
+ +<link linkend="handle-as-image">handle-as-image</link></literal> here.)
+ Remember that the type of the replacement image is chosen by the
+ <literal><link linkend="set-image-blocker">set-image-blocker</link></literal>
+ action. Since all URLs have matched the default section with its
+ <literal>+<link linkend="set-image-blocker">set-image-blocker</link>{pattern}</literal>
+ action before, it still applies and needn't be repeated:
+</para>
+
+<para>
+ <screen>
+# Known ad generators:
+#
+{ block-as-image }
+ar.atwola.com
+.ad.doubleclick.net
+.ad.*.doubleclick.net
+.a.yimg.com/(?:(?!/i/).)*$
+.a[0-9].yimg.com/(?:(?!/i/).)*$
+bs*.gsanet.com
+bs*.einets.com
+.qkimg.net</screen>
+</para>
+
+<para>
+ One of the most important jobs of <application>Privoxy</application>
+ is to block banners. A huge bunch of them are already <quote>blocked</quote>
+ by the <literal><link linkend="filter">filter</link>{banners-by-size}</literal>
+ 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
+ <literal><link linkend="block">block</link></literal> action to them.
+</para>
+<para>
+ 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:
+</para>
+
+<para>
+ <screen>
+##########################################################################
+# Block these fine banners:
+##########################################################################
+{ <link linkend="BLOCK">+block</link> }
+
+# 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</screen>
+</para>
+
+<para>
+ You wouldn't believe how many advertisers actually call their banner
+ servers ads.<replaceable>company</replaceable>.com, or call the directory
+ in which the banners are stored simply <quote>banners</quote>. So the above
+ generic patterns are surprisingly effective.
+</para>
+<para>
+ But being very generic, they necessarily also catch URLs that we don't want
+ to block. The pattern <literal>.*ads.</literal> e.g. catches
+ <quote>nasty-<emphasis>ads</emphasis>.nasty-corp.com</quote> as intended,
+ but also <quote>downlo<emphasis>ads</emphasis>.sourcefroge.net</quote> or
+ <quote><emphasis>ads</emphasis>l.some-provider.net.</quote> So here come some
+ well-known exceptions to the <literal>+<link linkend="BLOCK">block</link></literal>
+ section above.
+</para>
+<para>
+ Note that these are exceptions to exceptions from the default! Consider the URL
+ <quote>downloads.sourcefroge.net</quote>: Initially, all actions are deactivated,
+ so it wouldn't get blocked. Then comes the defaults section, which matches the
+ URL, but just deactivates the <literal><link linkend="BLOCK">block</link></literal>
+ action once again. Then it matches <literal>.*ads.</literal>, an exception to the
+ general non-blocking policy, and suddenly
+ <literal><link linkend="BLOCK">+block</link></literal> applies. And now, it'll match
+ <literal>.*loads.</literal>, where <literal><link linkend="BLOCK">-block</link></literal>
+ applies, so (unless it matches <emphasis>again</emphasis> further down) it ends up
+ with no <literal><link linkend="BLOCK">block</link></literal> action applying.
+</para>
+
+<para>
+ <screen>
+##########################################################################
+# Save some innocent victims of the above generic block patterns:
+##########################################################################
+
+# By domain:
+#
+{ -<link linkend="BLOCK">block</link> }
+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</screen>
+</para>
+
+<para>
+ Filtering source code can have nasty side effects,
+ so make an exception for our friends at sourceforge.net,
+ and all paths with <quote>cvs</quote> in them. Note that
+ <literal>-<link linkend="FILTER">filter</link></literal>
+ disables <emphasis>all</emphasis> filters in one fell swoop!
+</para>
+
+<para>
+ <screen>
+# Don't filter code!
+#
+{ -<link linkend="FILTER">filter</link> }
+/.*cvs
+.sourceforge.net</screen>
+</para>
+
+<para>
+ The actual <filename>default.action</filename> is of course more
+ comprehensive, but we hope this example made clear how it works.
+</para>
+
+</sect3>
+
+<sect3><title>user.action</title>
+
+<para>
+ 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'd maybe 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 <filename>user.action</filename>, which is parsed after all other
+ actions files and hence has the last word, over-riding any previously
+ defined actions. <filename>user.action</filename> is also a
+ <emphasis>safe</emphasis> place for your personal settings, since
+ <filename>default.action</filename> is actively maintained by the
+ <application>Privoxy</application> developers and you'll probably want
+ to install updated versions from time to time.
+</para>
+
+<para>
+ So let's look at a few examples of things that one might typically do in
+ <filename>user.action</filename>:
+</para>
+
+
+<!-- brief sample user.action here -->
+
+<para>
+ <screen>
+# My user.action file. <fred@foobar.com></screen>
+</para>
+
+<para>
+ As <link linkend="aliases">aliases</link> are local to the actions
+ file that they are defined in, you can't use the ones from
+ <filename>default.action</filename>, unless you repeat them here:
+</para>
+
+<para>
+ <screen>
+# (Re-)define aliases for this file:
+#
+{{alias}}
+-crunch-all-cookies = -crunch-incoming-cookies -crunch-outgoing-cookies
+mercy-for-cookies = -crunch-all-cookies -session-cookies-only
+fragile = -block -crunch-all-cookies -filter -fast-redirects -hide-referer -kill-popups
+shop = mercy-for-cookies -filter{popups} -kill-popups
+allow-ads = -block -filter{banners-by-size} # (see below)</screen>
+
+</para>
+
+<para>
+ 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
+ <literal>mercy-for-cookies</literal> alias defined above does exactly
+ that, i.e. it disables crunching of cookies in any direction, and
+ processing of cookies to make them temporary.
+</para>