[privoxy.git] / doc / source / user-manual.sgml

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<!entity supported SYSTEM "supported.sgml">
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<!entity copyright SYSTEM "copyright.sgml">
<!entity p-version "2.9.14">
<!entity p-status "beta">
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<!entity % p-doc "INCLUDE">        <!-- and we are a formal doc           -->
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<!--
 File        :  $Source: /cvsroot/ijbswa/current/doc/source/user-manual.sgml,v $

 Purpose     :  user manual
                This file belongs into
                ijbswa.sourceforge.net:/home/groups/i/ij/ijbswa/htdocs/
                
 $Id: user-manual.sgml,v 1.94 2002/04/26 05:24:36 hal9 Exp $

 Written by and Copyright (C) 2001 the SourceForge
 Privoxy team. http://www.privoxy.org/

 Based on the Internet Junkbuster originally written
 by and Copyright (C) 1997 Anonymous Coders and 
 Junkbusters Corporation.  http://www.junkbusters.com


 ========================================================================
 NOTE: Please read developer-manual/documentation.html before touching 
 anything in this, or other Privoxy documentation.
 ========================================================================

-->

<article id="index">
<artheader>
<title>Privoxy User Manual</title>

<pubdate>$Id: user-manual.sgml,v 1.94 2002/04/26 05:24:36 hal9 Exp $</pubdate>

<authorgroup>
 <author>
  <affiliation>
   <orgname>By: Privoxy Developers</orgname>
   </affiliation>
 </author>
</authorgroup>

<abstract>
<![%dummy;[
 <para>
 <comment>
  This is here to keep vim syntax file from breaking :/
  If I knew enough to fix it, I would.
  PLEASE DO NOT REMOVE! HB: hal@foobox.net
 </comment>
 </para>
]]>

 <para>
  The user manual gives users information on how to install, configure and use
  <ulink
  url="http://www.privoxy.org/"><application>Privoxy</application></ulink>.
  </para>

<!-- Include privoxy.sgml boilerplate: -->
 &p-intro;
<!-- end privoxy.sgml -->

 <para>
  You can find the latest version of the user manual at  <ulink
  url="http://www.privoxy.org/user-manual/">http://www.privoxy.org/user-manual/</ulink>.
  Please see the <ulink url="contact.html">Contact section</ulink> on how to
  contact the developers.
  </para>

<!--   <para> -->
<!--    Feel free to send a note to the developers at <email>ijbswa-developers@lists.sourceforge.net</email>. -->
<!--   </para> -->
</abstract>

</artheader>

<!--   ~~~~~       New section      ~~~~~     -->
<sect1 id="intro" label=""><title></title>
<!-- dummy section to force TOC on page by itself -->
<!-- DO NOT REMOVE! please ;) -->
<para> </para>
</sect1>

<!--   ~~~~~       New section      ~~~~~     -->
<sect1 label="1" id="introduction"><title>Introduction</title>
<para>
 This documentation is included with the current &p-status; version of
 <application>Privoxy</application>, v.&p-version;<![%p-not-stable;[, 
 and is mostly complete at this point. The most up to date reference for the
 time being is still the comments in the source files and in the individual
 configuration files. Development of version 3.0 is currently nearing
 completion, and includes many significant changes and enhancements over
 earlier versions. The target release date for
 stable v3.0 is <quote>soon</quote> ;-)]]>.
</para>

<!-- include only in non-stable versions -->
<![%p-not-stable;[
<para>
 Since this is a &p-status; version, not all new features are well tested. This
 documentation may be slightly out of sync as a result (especially with 
 CVS sources). And there <emphasis>may be</emphasis> bugs, though hopefully
 not many! 
</para>
]]>

<!--   ~~~~~       New section      ~~~~~     -->
<sect2 id="features"><title>Features</title>
<para>
 In addition to <application>Internet Junkbuster's</application> traditional
 features of ad and banner blocking and cookie management,
 <application>Privoxy</application> provides new features<![%p-not-stable;[,
 some of them currently under development]]>:
</para>
<!-- Include newfeatures.sgml boilerplate here: -->
 &newfeatures;
<!-- end boilerplate -->
</sect2>

</sect1>

<!--  ~  End section  ~  -->


<!--   ~~~~~       New section      ~~~~~     -->
<sect1 id="installation"><title>Installation</title>

<para>
 <application>Privoxy</application> is available both in convenient pre-compiled
 packages for a wide range of operating systems, and as raw source code.
 For most users, we recommend using the packages, which can be downloaded from our
 <ulink url="http://sourceforge.net/projects/ijbswa/">Privoxy Project
 Page</ulink>. For installing and compiling the source code, please look 
 into our Developer Manual.
</para>

<para>
 If you like to live on the bleeding edge and are not afraid of using
 possibly unstable development versions, you can check out the up-to-the-minute
 version directly from <ulink url="http://sourceforge.net/cvs/?group_id=11118">the
 CVS repository</ulink> or simply download <ulink
 url="http://cvs.sourceforge.net/cvstarballs/ijbswa-cvsroot.tar.gz">the nightly CVS
 tarball.</ulink> Again, we refer you to the Developer Manual.
</para>

<!-- Include supported.sgml boilerplate -->
 &supported; 
<!-- end boilerplate -->

<para>
 Note: If you have a previous <application>Junkbuster</application> or
 <application>Privoxy</application> installation on your system, you
 will need to remove it.  Some platforms do this for you as part 
 of their installation procedure. (See below for your platform).
</para>

<para>
 In any case <emphasis>be sure to backup your old configuration
 if it is valuable to you.</emphasis> See the
 <link linkend="upgradersnote">note to upgraders</link> section
 below.
</para>

<!--   ~~~~~       New section      ~~~~~     -->
<sect2 id="installation-pack-rpm"><title>Red Hat and SuSE RPMs</title>

<para>
 RPMs can be installed with <literal>rpm -Uvh privoxy-&p-version;-1.rpm</literal>,
 and will use <filename>/etc/privoxy</filename> for the location 
 of configuration files.
</para>

<para>
 Note that on Red Hat, <application>Privoxy</application> will
 <emphasis>not</emphasis> be automatically started on system boot. You will
 need to enable that using <command>chkconfig</command>,
 <command>ntsysv</command>, or similar methods. Note that SuSE will 
automatically start Privoxy in the boot process.
</para>

<para>
 If you have problems with failed dependencies, try rebuilding the SRC RPM: 
 <literal>rpm --rebuild privoxy-&p-version;-1.src.rpm;</literal>. This 
 will use your locally installed libraries and RPM version. 
</para>

<para>
 Also note that if you have a <application>Junkbuster</application> RPM installed
 on your system, you need to remove it first, because the packages conflict.
 Otherwise, RPM will try to remove <application>Junkbuster</application>
 automatically, before installing <application>Privoxy</application>.
</para>
</sect2>

<!--   ~~~~~       New section      ~~~~~     -->
<sect2 id="installation-deb"><title>Debian</title>
<para>
 FIXME.
</para>
</sect2>

<!--   ~~~~~       New section      ~~~~~     -->
<sect2 id="installation-pack-win"><title>Windows</title>

<para>
 Just double-click the installer, which will guide you through
 the installation process. You will find the configuration files
 in the same directory as you installed Privoxy in. We do not
 use the registry of Windows. 
</para>
</sect2>

<!--   ~~~~~       New section      ~~~~~     -->
<sect2 id="installation-pack-bintgz"><title>Solaris, NetBSD, FreeBSD, HP-UX</title>

<para>
 Create a new directory, <literal>cd</literal> to it, then unzip and
 untar the archive. For the most part, you'll have to figure out where
 things go. FIXME.
</para>
</sect2>

<!--   ~~~~~       New section      ~~~~~     -->
<sect2 id="installation-os2"><title>OS/2</title>

<para>
 First, make sure that no previous installations of
 <application>Junkbuster</application> and / or 
 <application>Privoxy</application> are left on your
 system. You can do this by 
</para>

<para>
 Then, just double-click the WarpIN self-installing archive, which will
 guide you through the installation process. A shadow of the
 <application>Privoxy</application> executable will be placed in your
 startup folder so it will start automatically whenever OS/2 starts.
</para>

<para>
 The directory you choose to install <application>Privoxy</application>
 into will contain all of the configuration files.
</para>
</sect2>

<!--   ~~~~~       New section      ~~~~~     -->
<sect2 id="installation-mac"><title>Max OSX</title>
<para>
 Unzip the downloaded package (you can either double-click on the file
 in the finder, or on the desktop if you downloaded it there).  Then,
 double-click on the package installer icon and follow the installation
 process.
 <application>Privoxy</application> will be installed in the subdirectory
 <literal>/Applications/Privoxy.app</literal>.
 <application>Privoxy</application> will set itself up to start 
 automatically on system bring-up via
 <literal>/System/Library/StartupItems/Privoxy</literal>.
</para>
</sect2>

<!--   ~~~~~       New section      ~~~~~     -->
<sect2 id="installation-amiga"><title>AmigaOS</title>
<para>
 Copy and then unpack the <filename>lha</filename> archive to a suitable location. 
 All necessary files will be installed into <application>Privoxy</application>
 directory, including all configuration and log files. To uninstall, just 
 remove this directory.
</para>
<para>
 Start <application>Privoxy</application> (with RUN &lt;&gt;NIL:) in your
 <filename>startnet</filename> script (AmiTCP), in
 <filename>s:user-startup</filename> (RoadShow), as startup program in your
 startup script (Genesis), or as startup action (Miami and MiamiDx). 
 <application>Privoxy</application> will automatically quit when you quit your
 TCP/IP stack (just ignore the harmless warning your TCP/IP stack may display that
 <application>Privoxy</application> is still running).
</para>
</sect2>
</sect1>

<!--  ~  End section  ~  -->

<!--   ~~~~~       New section      ~~~~~     -->
<sect1 id="upgradersnote">
<title>Note to Upgraders</title>
<para>
 There are very significant changes from older versions of 
 <application>Junkbuster</application> to the current
 <application>Privoxy</application>. Configuration is substantially 
 changed. <application>Junkbuster 2.0.x</application> and earlier 
 configuration files will not migrate. The functionality of the old
 <filename>blockfile</filename>, <filename>cookiefile</filename> and
 <filename>imagelist</filename>, are now combined into the
 <quote>actions files</quote>.  <filename>default.action</filename>, 
 is the main actions file. Local exceptions should best be put into 
 <filename>user.action</filename>.
</para>
<para>
 A <quote>filter file</quote> (typically <filename>default.filter</filename>)
 is new as of <application>Privoxy 2.9.x</application>, and provides some
 of the new sophistication (explained below). <filename>config</filename> is 
 much the same as before.
</para>
<para>
 If upgrading from a 2.0.x version, you will have to use the new config 
 files, and possibly adapt any personal rules from your older files.
 When porting personal rules over from the old <filename>blockfile</filename>
 to the new actions files, please note that even the pattern syntax has
 changed. If upgrading from 2.9.x development versions, it is still
 recommended to use the new configuration files.
</para>
<para>
 A quick list of things to be aware of before upgrading: 
</para>

<para>
 <itemizedlist>

 <listitem>
  <para>
   The default listening port is now 8118 due to a conflict with another 
   service (NAS).
  </para>
 </listitem>  
 <listitem>
  <para>  
    Some installers may remove earlier versions completely. Save any 
    important configuration files!
  </para>
 </listitem>
 <listitem>
  <para>
   <application>Privoxy</application> is controllable with a web browser 
   at the special URL: <ulink
   url="http://config.privoxy.org/">http://config.privoxy.org/</ulink>
   (Shortcut: <ulink url="http://p.p/">http://p.p/</ulink>). Many
   aspects of configuration can be done here, including temporarily disabling
   <application>Privoxy</application>.
  </para>
 </listitem> 
 <listitem>
  <para>
   The primary configuration file for cookie management, ad and banner 
   blocking, and many other aspects of <application>Privoxy</application>
   configuration is in the <quote>actions</quote> files. It is strongly
   recommended to become familiar with the new actions concept below, 
   before modifying these files. Locally defined rules 
   should go into <filename>user.action</filename>.
  </para>
 </listitem> 
  <listitem>
  <para>
<!-- I think it is best to keep this somewhat vague, in case  -->
<!-- the situation changes under our feet. -->   
   Some installers may not automatically start
   <application>Privoxy</application> after installation.
  </para>
 </listitem> 

 </itemizedlist>
</para>
</sect1>

<!--   ~~~~~       New section      ~~~~~     -->
<sect1 id="quickstart"><title>Quickstart to Using <application>Privoxy</application></title>
<para>
 <itemizedlist>

 <listitem>
  <para>
  Install <application>Privoxy</application>. See the section <link linkend="installation">Installing</link>.
  </para>
 </listitem>  

 <listitem>
  <para>
  Start <application>Privoxy</application>. See the section <link linkend="startup">Starting <application>Privoxy</application></link>.
  </para>
 </listitem>  

 <listitem>
  <para>
  Change your browser's configuration to use the proxy <literal>localhost</literal> on port
  <literal>8118</literal>. See the section <link linkend="startup">Starting <application>Privoxy</application></link>.
  </para>
 </listitem>  

 <listitem>
  <para>
  Enjoy surfing with enhanced comfort and privacy. Please see the section
  <link linkend="contact">Contacting the Developers</link> on how to report
  bugs or problems with websites or to get help. You may want to change the
  file <filename>user.action</filename> to further tweak your new browsing
  experience.
  </para>
 </listitem>  

 </itemizedlist>
</para>

</sect1>

<!--   ~~~~~       New section      ~~~~~     -->
<sect1 id="startup">
<title>Starting <application>Privoxy</application></title>
<para>
 Before launching <application>Privoxy</application> for the first time, you 
 will want to configure your browser(s) to use <application>Privoxy</application>
 as a HTTP and HTTPS proxy. The default is localhost for the proxy address,
 and port 8118 (earlier versions used port 8000). This is the one
 configuration step that must be done! 
</para>
 
<para> 
 With <application>Netscape</application> (and
 <application>Mozilla</application>), this can be set under <literal>Edit
 -&gt; Preferences -&gt; Advanced -&gt; Proxies -&gt; HTTP Proxy</literal>.
 For <application>Internet Explorer</application>: <literal>Tools -&gt;
 Internet Properties -&gt; Connections -&gt; LAN Setting</literal>. Then,
 check <quote>Use Proxy</quote> and fill in the appropriate info (Address:
 localhost, Port: 8118). Include if HTTPS proxy support too.
</para>

<para>
 After doing this, flush your browser's disk and memory caches to force a
 re-reading of all pages and to get rid of any ads that may be cached. You 
 are now ready to start enjoying the benefits of using
 <application>Privoxy</application>!
</para>


<para>
 <application>Privoxy</application> is typically started by specifying the
 main configuration file to be used on the command line. Example Unix startup
 command:
</para>

<para>
 <screen>
 
 # /usr/sbin/privoxy /etc/privoxy/config
</screen>
</para>

<para>
 See <link linkend="cmdoptions">below</link> for other command line options.
</para>

<para>
 An init script is provided for SuSE and Red Hat.
</para>

<para>
 For for SuSE: <command>rcprivoxy start</command>
</para>

<para>
 For Red Hat and Debian: <command>/etc/rc.d/init.d/privoxy start</command>
</para>


<para>
 If no configuration file is specified on the command line,
 <application>Privoxy</application> will look for a file named
 <filename>config</filename> in the current directory. Except on Win32 where
 it will try <filename>config.txt</filename>. If no file is specified on the
 command line and no default configuration file can be found, 
 <application>Privoxy</application> will fail to start.
</para>


<para>
 The included default configuration files should give a reasonable starting
 point. Most of the per site configuration is done in the
 <quote>actions</quote> files. These are where various cookie actions are
 defined, ad and banner blocking, and other aspects of
 <application>Privoxy</application> configuration. There are several such
 files included, with varying levels of aggressiveness. 
</para>

<para>
 You will probably want to keep an eye out for sites for which you may prefer
 persistent cookies, and add these to your actions configuration as needed. By
 default, most of these will be accepted only during the current browser
 session (aka <quote>session cookies</quote>), unless you add them to the
 configuration. If you want the browser to handle this instead, you will need
 to edit <filename>user.action</filename> (or through the web based interface)
 and disable this feature. If you use more than one browser, it would make
 more sense to let <application>Privoxy</application> handle this. In which
 case, the browser(s) should be set to accept all cookies.
</para>

<para>
 Another feature where you will probably want to define exceptions for trusted
 sites is the popup-killing (through the <literal>+popup</literal> and
 <literal>+filter{popups}</literal> actions), because your favorite shopping,
 banking, or leisure site may need popups (explained below). 
</para>

<para>
 <application>Privoxy</application> is HTTP/1.1 compliant,  but not all of
 the optional 1.1 features are as yet supported. In the unlikely event that
 you experience inexplicable problems with browsers that use HTTP/1.1 per default
 (like <application>Mozilla</application> or recent versions of I.E.), you might
 try to force HTTP/1.0 compatibility. For Mozilla, look under <literal>Edit -&gt;
 Preferences -&gt; Debug -&gt; Networking</literal>.
 Alternatively, set the <quote>+downgrade-http-version</quote> config option in
 <filename>default.action</filename> which will downgrade your browser's HTTP
 requests from HTTP/1.1 to HTTP/1.0 before processing them.
</para>

<para>
 After running <application>Privoxy</application> for a while, you can 
 start to fine tune the configuration to suit your personal, or site, 
 preferences and requirements. There are many, many aspects that can 
 be customized. <quote>Actions</quote> 
 can be adjusted by pointing your browser to 
 <ulink url="http://config.privoxy.org/">http://config.privoxy.org/</ulink>
 (shortcut: <ulink url="http://p.p/">http://p.p/</ulink>), 
 and then follow the link to <quote>View &#38; Change the Current Configuration</quote>. 
 (This is an internal page and does not require Internet access.)
</para>

<para>
 In fact, various aspects of <application>Privoxy</application>
 configuration can be viewed from this page, including 
 current configuration parameters, source code version numbers, 
 the browser's request headers, and <quote>actions</quote> that apply 
 to a given URL. In addition to the actions file 
 editor mentioned above, <application>Privoxy</application> can also 
 be turned <quote>on</quote> and <quote>off</quote> (toggled) from this page.
</para>

<para>
 If you encounter problems, try loading the page without
 <application>Privoxy</application>. If that helps, enter the URL where
 you have the problems into <ulink url="http://p.p/show-url-info">the browser
 based rule tracing utility</ulink>. See which rules apply and why, and
 then try turning them off for that site one after the other, until the problem
 is gone. When you have found the culprit, you might want to turn the rest on
 again.
</para>

<para>
 If the above paragraph sounds gibberish to you, you might want to <ulink
 url="configuration.html#ACTIONSFILE">read more about the actions concept</ulink>
 or even dive deep into the <ulink url="appendix.html#ACTIONSANAT">Appendix
 on actions</ulink>.
</para>

<para>
 If you can't get rid of the problem at all, think you've found a bug in
 Privoxy, want to propose a new feature or smarter rules, please see the 
 section <ulink url="contact.html"><quote>Contacting the
 Developers</quote></ulink> below. 
</para>

<!--   ~~~~~       New section      ~~~~~     -->
<sect2 id="cmdoptions">
<title>Command Line Options</title>
<para>
 <application>Privoxy</application> may be invoked with the following
 command-line options:
</para>

<para>
 <itemizedlist>

 <listitem>
  <para>
    <emphasis>--version</emphasis>
  </para>
  <para>
     Print version info and exit. Unix only.
  </para>
 </listitem> 
 <listitem>
  <para>
    <emphasis>--help</emphasis>
  </para>
  <para>
   Print short usage info and exit. Unix only.
  </para>
 </listitem> 
 <listitem>
  <para>
   <emphasis>--no-daemon</emphasis>
  </para>
  <para>
   Don't become a daemon, i.e. don't fork and become process group
   leader, and don't detach from controlling tty. Unix only.
  </para>
 </listitem> 
 <listitem>
  <para>
   <emphasis>--pidfile FILE</emphasis>
  
  </para>
  <para>
   On startup, write the process ID to <emphasis>FILE</emphasis>. Delete the
   <emphasis>FILE</emphasis> on exit. Failure to create or delete the
   <emphasis>FILE</emphasis> is non-fatal. If no <emphasis>FILE</emphasis>
   option is given, no PID file will be used. Unix only.
  </para>
 </listitem> 
 <listitem>
  <para>
   <emphasis>--user USER[.GROUP]</emphasis>
  
  </para>
  <para>
   After (optionally) writing the PID file, assume the user  ID  of
   <emphasis>USER</emphasis>, and if included the GID of GROUP.  Exit if the
   privileges are not sufficient to do so. Unix only.
  </para>
 </listitem> 
 <listitem>
  <para>
    <emphasis>configfile</emphasis>
  </para>
  <para>
    If no <emphasis>configfile</emphasis> is included on the command line, 
    <application>Privoxy</application> will look for a file named 
    <quote>config</quote> in the current directory (except on Win32 
    where it will look for <quote>config.txt</quote> instead). Specify 
    full path to avoid confusion. If no config file is found, 
    <application>Privoxy</application> will fail to start.
  </para>
 </listitem> 

 </itemizedlist>
</para>

</sect2>

</sect1>

<!--  ~  End section  ~  -->


<!--   ~~~~~       New section      ~~~~~     -->
<sect1 id="configuration"><title><application>Privoxy</application> Configuration</title>
 <para>
  All <application>Privoxy</application> configuration is stored  
  in text files. These files can be edited with a text editor.
  Many important aspects of <application>Privoxy</application> can 
  also be controlled easily with a web browser.
 </para>


<!--   ~~~~~       New section      ~~~~~     -->

<sect2>
<title>Controlling <application>Privoxy</application> with Your Web Browser</title>
<para>
 <application>Privoxy</application>'s user interface can be reached through the special 
 URL <ulink url="http://config.privoxy.org/">http://config.privoxy.org/</ulink>
 (shortcut: <ulink url="http://p.p/">http://p.p/</ulink>), 
 which is a built-in page and works without Internet access.
 You will see the following section:

</para>

<!-- Needs to be put in a table and colorized  -->
<screen>
 <msgtext>
 <bridgehead renderas="sect2">Privoxy Menu</bridgehead>

 <simplelist>
 <member>
  &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&squf;&nbsp;&nbsp;<ulink url="http://config.privoxy.org/show-status">View & change the current configuration</ulink>
 </member>
 <member>
  &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&squf;&nbsp;&nbsp;<ulink url="http://config.privoxy.org/show-version">View the source code version numbers</ulink>
 </member>
 <member>
  &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&squf;&nbsp;&nbsp;<ulink url="http://config.privoxy.org/show-request">View the request headers.</ulink>
 </member>
 <member>
  &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&squf;&nbsp;&nbsp;<ulink url="http://config.privoxy.org/show-url-info">Look up which actions apply to a URL and why</ulink>
 </member>
 <member>
  &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&squf;&nbsp;&nbsp;<ulink url="http://config.privoxy.org/toggle">Toggle Privoxy on or off</ulink>
 </member>
 </simplelist>
 </msgtext>
</screen>


<para>
 This should be self-explanatory. Note the first item leads to an editor for the
 <quote>actions list</quote>, which is where the ad, banner, cookie,
 and URL blocking magic is configured as well as other advanced features of
 <application>Privoxy</application>. This is an easy way to adjust various
 aspects of <application>Privoxy</application> configuration. The actions
 file, and other configuration files, are explained in detail below. 
</para>

<para>
 <quote>Toggle Privoxy On or Off</quote> is handy for sites that might 
 have problems with your current actions and filters. You can in fact use
 it as a test to see whether it is <application>Privoxy</application> 
 causing the problem or not. <application>Privoxy</application> continues 
 to run as a proxy in this case, but all filtering is disabled. There
 is even a toggle <link linkend="bookmarklets">Bookmarklet</link> offered, so
 that you can toggle <application>Privoxy</application> with one click from
 your browser.
</para>

</sect2>

<!--  ~  End section  ~  -->




<!--   ~~~~~       New section      ~~~~~     -->

<sect2 id="confoverview">
<title>Configuration Files Overview</title>
<para>
 For Unix, *BSD and Linux, all configuration files are located in
 <filename>/etc/privoxy/</filename> by default. For MS Windows, OS/2, and
 AmigaOS these are all in the same directory as the 
 <application>Privoxy</application> executable. <![%p-not-stable;[ The name
 and number of configuration files has changed from previous versions, and is
 subject to change as development progresses.]]>
</para>

<para>
 The installed defaults provide a reasonable starting point, though 
 some settings may be aggressive by some standards. For the time being, the
 principle configuration files are:
</para>

<para>
 <itemizedlist>

  <listitem>
   <para>
     The main configuration file is named <link linkend="config">config</link>
     on Linux, Unix, BSD, OS/2, and AmigaOS and <filename>config.txt</filename>
     on Windows. This is a required file.
   </para>
  </listitem> 

  <listitem>
   <para>
    <filename>default.action</filename> (the main <link linkend="actions-file">actions file</link>) is used to define
    the default settings for various <quote>actions</quote> relating to images, banners, 
    pop-ups, access restrictions, banners and cookies.
   </para>
   <para>
    Multiple actions files may be defined in <filename>config</filename>. These 
    are processed in the order they are defined. Local customizations and locally 
    preferred exceptions to the default policies as defined in
    <filename>default.action</filename> are probably best applied in
    <filename>user.action</filename>, which should be preserved across
    upgrades. <filename>standard.action</filename> is also included. This is mostly 
    for <application>Privoxy's</application> internal use.
   </para>
   <para>    
    There is also a web based editor that can be accessed from
    <ulink
    url="http://config.privoxy.org/show-status/">http://config.privoxy.org/show-status/</ulink>
    (Shortcut: <ulink
    url="http://p.p/show-status/">http://p.p/show-status/</ulink>) for the
    various actions files. 
   </para>
  </listitem> 

  <listitem>
   <para>
    <filename>default.filter</filename> (the <link linkend="filter-file">filter
    file</link>) can be used to re-write the raw page content, including
    viewable text as well as embedded HTML and JavaScript, and whatever else
    lurks on any given web page. The filtering jobs are only pre-defined here;
    whether to apply them or not is up to the actions files.
   </para>
  </listitem> 

 </itemizedlist>
</para>

<para>
 All files use the <quote><literal>#</literal></quote> character to denote a
 comment (the rest of the line will be ignored) angd understand line continuation
 through placing a backslash ("<literal>\</literal>") as the very last character
 in a line. If the <literal>#</literal> is preceded by a backslash, it looses
 its special function. Placing a <literal>#</literal> in front of an otherwise
 valid configuration line to prevent it from being interpreted is called "commenting
 out" that line.
</para>

<para>
 The actions files and <filename>default.filter</filename> 
 can use Perl style <link linkend="regex">regular expressions</link> for
 maximum flexibility. 
</para>

<para>
 After making any changes, there is no need to restart
 <application>Privoxy</application> in order for the changes to take
 effect. <application>Privoxy</application> detects such changes 
 automatically. Note, however, that it may take one or two additional
 requests for the change to take effect. When changing the listening address
 of <application>Privoxy</application>, these <quote>wake up</quote> requests
 must obviously be sent to the <emphasis>old</emphasis> listening address.
</para>

<![%p-not-stable;[
<para>
 While under development, the configuration content is subject to change. 
 The below documentation may not be accurate by the time you read this. 
 Also, what constitutes a <quote>default</quote> setting, may change, so 
 please check all your configuration files on important issues.
</para>
]]>
</sect2>


<!--   ~~~~~       New section      ~~~~~     -->

<sect2 id="config">
<title>The Main Configuration File</title>
<para>
 Again, the main configuration file is named <filename>config</filename> on
 Linux/Unix/BSD and OS/2, and <filename>config.txt</filename> on Windows.
 Configuration lines consist of an initial keyword followed by a list of
 values, all separated by whitespace (any number of spaces or tabs). For
 example:
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
  <emphasis>confdir /etc/privoxy</emphasis>
   </literallayout>
  </msgtext>
 </literal> 
</para>

<para>
 Assigns the value <literal>/etc/privoxy</literal> to the option
 <literal>confdir</literal> and thus indicates that the configuration
 directory is named <quote>/etc/privoxy/</quote>.
</para>

<para>
 All options in the config file except for <literal>confdir</literal> and
 <literal>logdir</literal> are optional. Watch out in the below description
 for what happens if you leave them unset.
</para>

<para>
 The main config file controls all aspects of <application>Privoxy</application>'s
 operation that are not location dependent (i.e. they apply universally, no matter
 where you may be surfing).
</para>


<!--   ~~~~~       New section      ~~~~~     -->

<sect3 id="conf-log-loc">
<title>Configuration and Log File Locations</title>

<para>
 <application>Privoxy</application> can (and normally does) use a number of
 other files for additional configuration and logging.
 This section of the configuration file tells <application>Privoxy</application>
 where to find those other files. 
</para>


<sect4 id="confdir"><title>confdir</title>

<variablelist>
 <varlistentry>
  <term>Specifies:</term>
  <listitem>
   <para>The directory where the other configuration files are located</para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Type of value:</term>
  <listitem>
   <para>Path name</para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Default value:</term>
  <listitem>
   <para>/etc/privoxy (Unix) <emphasis>or</emphasis> <application>Privoxy</application> installation dir (Windows) </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Effect if unset:</term>
  <listitem>
   <para><emphasis>Mandatory</emphasis></para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Notes:</term>
  <listitem>
   <para>
    No trailing <quote><literal>/</literal></quote>, please
   </para>
   <para>
    When development goes modular and multi-user, the blocker, filter, and
    per-user config will be stored in subdirectories of <quote>confdir</quote>.
    For now, the configuration directory structure is flat, except for 
    <filename>confdir/templates</filename>, where the HTML templates for CGI 
    output reside (e.g. <application>Privoxy's</application> 404 error page). 
   </para>
  </listitem>
 </varlistentry>
</variablelist>
</sect4>


<sect4 id="logdir"><title>logdir</title>

<variablelist>
 <varlistentry>
  <term>Specifies:</term>
  <listitem>
   <para>
    The directory where all logging takes place (i.e. where <filename>logfile</filename> and 
    <filename>jarfile</filename> are located) 
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Type of value:</term>
  <listitem>
   <para>Path name</para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Default value:</term>
  <listitem>
   <para>/var/log/privoxy (Unix) <emphasis>or</emphasis> <application>Privoxy</application> installation dir (Windows) </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Effect if unset:</term>
  <listitem>
   <para><emphasis>Mandatory</emphasis></para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Notes:</term>
  <listitem>
   <para>
    No trailing <quote><literal>/</literal></quote>, please
   </para>
  </listitem>
 </varlistentry>
</variablelist>
</sect4>

<sect4 id="actionsfile"><title>
<anchor id="default.action">
<anchor id="standard.action">
<anchor id="user.action">
actionsfile
</title>

<variablelist>
 <varlistentry>
  <term>Specifies:</term>
  <listitem>
   <para>
    The <link linkend="actions">actions</link> file(s) to use
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Type of value:</term>
  <listitem>
   <para>File name, relative to <literal>confdir</literal></para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Default value:</term>
  <listitem>
   <simplelist>
    <member>
     <msgtext><literallayout>  standard     # Internal purposes, recommended not editing</literallayout></msgtext>
    </member>
    <member>
     <msgtext><literallayout>  default      # Main actions file</literallayout></msgtext>
    </member>
    <member>
     <msgtext><literallayout>  user         # User customizations</literallayout></msgtext>
    </member>
   </simplelist>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Effect if unset:</term>
  <listitem>
   <para>
    No actions are taken at all. Simple neutral proxying. 
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Notes:</term>
  <listitem>
   <para>
    Multiple <literal>actionsfile</literal> lines are OK and are in fact recommended!
   </para>
   <para> 
    The default values include standard.action, which is used for internal
    purposes and should be loaded, default.action, which is the
    <quote>main</quote> actions file maintained by the developers, and
    <filename>user.action</filename>, where you can make your personal additions.
   </para>
   <para> 
    There is no point in using <application>Privoxy</application> without an actions file.
   </para>
  </listitem>
 </varlistentry>
</variablelist>
</sect4>

<sect4 id="filterfile"><title><anchor id="default.filter">filterfile</title>
<variablelist>
 <varlistentry>
  <term>Specifies:</term>
  <listitem>
   <para>
    The <link linkend="filter">filter</link> file to use
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Type of value:</term>
  <listitem>
   <para>File name, relative to <literal>confdir</literal></para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Default value:</term>
  <listitem>
   <para>default.filter (Unix) <emphasis>or</emphasis> default.filter.txt (Windows)</para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Effect if unset:</term>
  <listitem>
   <para>
    No textual content filtering takes place, i.e. all
    <literal>+filter{<replaceable class="parameter">name</replaceable>}</literal>
    actions in the actions files are turned off
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Notes:</term>
  <listitem>
   <para>
    The <quote>default.filter</quote> file contains content modification rules 
    that use <quote>regular expressions</quote>. These rules permit powerful
    changes on the content of Web pages, e.g., you could disable your favorite
    JavaScript annoyances, re-write the actual displayed text, or just have some
    fun replacing <quote>Microsoft</quote> with <quote>MicroSuck</quote> wherever
    it appears on a Web page.
   </para>
  </listitem>
 </varlistentry>
</variablelist>
</sect4>

<sect4 id="logfile"><title>logfile</title>

<variablelist>
 <varlistentry>
  <term>Specifies:</term>
  <listitem>
   <para>
    The log file to use
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Type of value:</term>
  <listitem>
   <para>File name, relative to <literal>logdir</literal></para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Default value:</term>
  <listitem>
   <para>logfile (Unix) <emphasis>or</emphasis> privoxy.log (Windows)</para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Effect if unset:</term>
  <listitem>
   <para>
    No log file is used, all log messages go to the console (<literal>stderr</literal>).
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Notes:</term>
  <listitem>
   <para>
    The windows version will additionally log to the console.
   </para>
   <para>
    The logfile is where all logging and error messages are written. The level
    of detail and number of messages are set with the <literal>debug</literal>
    option (see below). The logfile can be useful for tracking down a problem with
    <application>Privoxy</application> (e.g., it's not blocking an ad you
    think it should block) but in most cases you probably will never look at it.
   </para>
   <para>
    Your logfile will grow indefinitely, and you will probably want to
    periodically remove it.  On Unix systems, you can do this with a cron job
    (see <quote>man cron</quote>). For Red Hat, a <command>logrotate</command> 
    script has been included.
   </para> 
   <para>
    On SuSE Linux systems, you can place a line like <quote>/var/log/privoxy.*
    +1024k 644 nobody.nogroup</quote> in <filename>/etc/logfiles</filename>, with
    the effect that cron.daily will automatically archive, gzip, and empty the
    log, when it exceeds 1M size.
   </para>
  </listitem>
 </varlistentry>
</variablelist>
</sect4>

<sect4 id="jarfile"><title>jarfile</title>

<variablelist>
 <varlistentry>
  <term>Specifies:</term>
  <listitem>
   <para>
    The file to store intercepted cookies in
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Type of value:</term>
  <listitem>
   <para>File name, relative to <literal>logdir</literal></para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Default value:</term>
  <listitem>
   <para>jarfile (Unix) <emphasis>or</emphasis> privoxy.jar (Windows)</para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Effect if unset:</term>
  <listitem>
   <para>
    Intercepted cookies are not stored at all.
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Notes:</term>
  <listitem>
   <para>
    The jarfile may grow to ridiculous sizes over time.
   </para>
  </listitem>
 </varlistentry>
</variablelist>
</sect4>

<sect4 id="trustfile"><title>trustfile</title>

<variablelist>
 <varlistentry>
  <term>Specifies:</term>
  <listitem>
   <para>
    The trust file to use
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Type of value:</term>
  <listitem>
   <para>File name, relative to <literal>confdir</literal></para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Default value:</term>
  <listitem>
   <para><emphasis>Unset (commented out)</emphasis>. When activated: trust (Unix) <emphasis>or</emphasis> trust.txt (Windows)</para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Effect if unset:</term>
  <listitem>
   <para>
    The whole trust mechanism is turned off.
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Notes:</term>
  <listitem>
   <para>
    The trust mechanism is an experimental feature for building white-lists and should
    be used with care. It is <emphasis>NOT</emphasis> recommended for the casual user.
   </para>
   <para>
    If you specify a trust file, <application>Privoxy</application> will only allow
    access to sites that are named in the trustfile. 
    You can also mark sites as trusted referrers (with <literal>+</literal>), with
    the effect that access to untrusted sites will be granted, if a link from a
    trusted referrer was used.
    The link target will then be added to the <quote>trustfile</quote>.
    Possible applications include limiting Internet access for children.
   </para>
   <para>
    If you use <literal>+</literal> operator in the trust file, it may grow considerably over time.
   </para>
  </listitem>
 </varlistentry>
</variablelist>
</sect4>

</sect3>

<!--  ~  End section  ~  -->



<!--   ~~~~~       New section      ~~~~~     -->

<sect3 id="local-set-up">
<title>Local Set-up Documentation</title>

  <para>
    If you intend to operate <application>Privoxy</application> for more users
    that just yourself, it might be a good idea to let them know how to reach
    you, what you block and why you do that, your policies etc.
   </para>

<sect4 id="trust-info-url"><title>trust-info-url</title>

<variablelist>
 <varlistentry>
  <term>Specifies:</term>
  <listitem>
   <para>
    A URL to be displayed in the error page that users will see if access to an untrusted page is denied.    
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Type of value:</term>
  <listitem>
   <para>URL</para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Default value:</term>
  <listitem>
   <para>Two example URL are provided</para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Effect if unset:</term>
  <listitem>
   <para>
    No links are displayed on the "untrusted" error page.
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Notes:</term>
  <listitem>
   <para>
    The value of this option only matters if the experimental trust mechanism has been
    activated. (See <literal>trustfile</literal> above.)
   </para>
   <para>
    If you use the trust mechanism, it is a good idea to write up some on-line
    documentation about your trust policy and to specify the URL(s) here.
    Use multiple times for multiple URLs.
   </para>
   <para>
    The URL(s) should be added to the trustfile as well, so users don't end up
    locked out from the information on why they were locked out in the first place!
   </para>
  </listitem>
 </varlistentry>
</variablelist>
</sect4>

<sect4 id="admin-address"><title>admin-address</title>

<variablelist>
 <varlistentry>
  <term>Specifies:</term>
  <listitem>
   <para>
    An email address to reach the proxy administrator.
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Type of value:</term>
  <listitem>
   <para>Email address</para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Default value:</term>
  <listitem>
   <para><emphasis>Unset</emphasis></para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Effect if unset:</term>
  <listitem>
   <para>
    No email address is displayed on error pages and the CGI user interface.
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Notes:</term>
  <listitem>
    <para>
    If both <literal>admin-address</literal> and <literal>proxy-info-url</literal>
    are unset, the whole "Local Privoxy Support" box on all generated pages will
    not be shown.
   </para>  
  </listitem>
 </varlistentry>
</variablelist>
</sect4>

<sect4 id="proxy-info-url"><title>proxy-info-url</title>

<variablelist>
 <varlistentry>
  <term>Specifies:</term>
  <listitem>
   <para>
    A URL to documentation about the local <application>Privoxy</application> setup,
    configuration or policies.
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Type of value:</term>
  <listitem>
   <para>URL</para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Default value:</term>
  <listitem>
   <para><emphasis>Unset</emphasis></para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Effect if unset:</term>
  <listitem>
   <para>
    No link to local documentation is displayed on error pages and the CGI user interface.
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Notes:</term>
  <listitem>
   <para>
    If both <literal>admin-address</literal> and <literal>proxy-info-url</literal>
    are unset, the whole "Local Privoxy Support" box on all generated pages will
    not be shown.
   </para>  
   <para>
    This URL shouldn't be blocked ;-)
   </para> 
  </listitem>
 </varlistentry>
</variablelist>
</sect4>

</sect3>
<!--  ~  End section  ~  -->

<!--   ~~~~~       New section      ~~~~~     -->

<sect3 id="debugging">
<title>Debugging</title>

 <para>
  These options are mainly useful when tracing a problem.
  Note that you might also want to invoke
  <application>Privoxy</application> with the <literal>--no-daemon</literal>
  command line option when debugging.
 </para>

<sect4 id="debug"><title>debug</title>

<variablelist>
 <varlistentry>
  <term>Specifies:</term>
  <listitem>
   <para>
    Key values that determine what information gets logged.
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Type of value:</term>
  <listitem>
   <para>Integer values</para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Default value:</term>
  <listitem>
   <para>12289 (i.e.: URLs plus informational and warning messages)</para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Effect if unset:</term>
  <listitem>
   <para>
    Nothing gets logged.
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Notes:</term>
  <listitem>
   <para>
    The available debug levels are:
   </para>
   <para>
    <programlisting>
  debug         1 # show each GET/POST/CONNECT request
  debug         2 # show each connection status
  debug         4 # show I/O status
  debug         8 # show header parsing
  debug        16 # log all data into the logfile
  debug        32 # debug force feature
  debug        64 # debug regular expression filter 
  debug       128 # debug fast redirects
  debug       256 # debug GIF de-animation
  debug       512 # Common Log Format
  debug      1024 # debug kill pop-ups
  debug      4096 # Startup banner and warnings.
  debug      8192 # Non-fatal errors
</programlisting>
   </para>
   <para>
    To select multiple debug levels, you can either add them or use
    multiple <literal>debug</literal> lines.
   </para>
   <para>
    A debug level of 1 is informative because it will show you each request
    as it happens. <emphasis>1, 4096 and 8192 are highly recommended</emphasis>
    so that you will notice when things go wrong. The other levels are probably
    only of interest if you are hunting down a specific problem. They can produce
    a hell of an output (especially 16).
    <!-- LOL -->
   </para>
   <para>
    The reporting of <emphasis>fatal</emphasis> errors (i.e. ones which crash 
    <application>Privoxy</application>) is always on and cannot be disabled.
   </para>
   <para>
    If you want to use CLF (Common Log Format), you should set <quote>debug
    512</quote> <emphasis>ONLY</emphasis> and not enable anything else.
   </para>
  </listitem>
 </varlistentry>
</variablelist>
</sect4>

<sect4 id="single-threaded"><title>single-threaded</title>

<variablelist>
 <varlistentry>
  <term>Specifies:</term>
  <listitem>
   <para>
    Whether to run only one server thread
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Type of value:</term>
  <listitem>
   <para><emphasis>None</emphasis></para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Default value:</term>
  <listitem>
   <para><emphasis>Unset</emphasis></para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Effect if unset:</term>
  <listitem>
   <para>
    Multi-threaded (or, where unavailable: forked) operation, i.e. the ability to
    serve multiple requests simultaneously.
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Notes:</term>
  <listitem>
   <para>
    This option is only there for debug purposes and you should never
    need to use it. <emphasis>It will drastically reduce performance.</emphasis>
   </para>
  </listitem>
 </varlistentry>
</variablelist>
</sect4>

</sect3>

<!--   ~~~~~       New section      ~~~~~     -->

<sect3 id="access-control">
<title>Access Control and Security</title>

 <para>
  This section of the config file controls the security-relevant aspects
  of <application>Privoxy</application>'s configuration.
 </para>

<sect4 id="listen-address"><title>listen-address</title>

<variablelist>
 <varlistentry>
  <term>Specifies:</term>
  <listitem>
   <para>
    The IP address and TCP port on which <application>Privoxy</application> will
    listen for client requests.
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Type of value:</term>
  <listitem>
   <para>[<replaceable class="parameter">IP-Address</replaceable>]:<replaceable class="parameter">Port</replaceable></para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Default value:</term>
  <listitem>
   <para>localhost:8118</para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Effect if unset:</term>
  <listitem>
   <para>
    Bind to localhost (127.0.0.1), port 8118. This is suitable and recommended for
    home users who run <application>Privoxy</application> on the same machine as
    their browser.
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Notes:</term>
  <listitem>
   <para>
    You will need to configure your browser(s) to this proxy address and port.
   </para>
   <para>
    If you already have another service running on port 8118, or if you want to
    serve requests from other machines (e.g. on your local network) as well, you
    will need to override the default.
   </para>
   <para>
    If you leave out the IP address, <application>Privoxy</application> will
    bind to all interfaces (addresses) on your machine and may become reachable
    from the Internet. In that case, consider using access control lists (ACL's)
    (see <quote>ACLs</quote> below), or a firewall.
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Example:</term>
  <listitem>
   <para>
     Suppose you are running <application>Privoxy</application> on
     a machine which has the address 192.168.0.1 on your local private network
     (192.168.0.0) and has another outside connection with a different address.
     You want it to serve requests from inside only:
   </para>
   <para>
    <programlisting>
  listen-address  192.168.0.1:8118
</programlisting>
   </para>
  </listitem>
 </varlistentry>
</variablelist>
</sect4>

<sect4 id="toggle"><title>toggle</title>

<variablelist>
 <varlistentry>
  <term>Specifies:</term>
  <listitem>
   <para>
    Initial state of "toggle" status
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Type of value:</term>
  <listitem>
   <para>1 or 0</para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Default value:</term>
  <listitem>
   <para>1</para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Effect if unset:</term>
  <listitem>
   <para>
    Act as if toggled on
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Notes:</term>
  <listitem>
   <para>
    If set to 0, <application>Privoxy</application> will start in
    <quote>toggled off</quote> mode, i.e. behave like a normal, content-neutral
    proxy. See <literal>enable-remote-toggle</literal>
    below. This is not really useful anymore, since toggling is much easier
    via <ulink url="http://config.privoxy.org/toggle">the web
    interface</ulink> then via editing the <filename>conf</filename> file.
   </para>
   <para>
    The windows version will only display the toggle icon in the system tray
    if this option is present.
   </para>
  </listitem>
 </varlistentry>
</variablelist>
</sect4>


<sect4 id="enable-remote-toggle"><title>enable-remote-toggle</title>
<variablelist>
 <varlistentry>
  <term>Specifies:</term>
  <listitem>
   <para>
    Whether or not the <ulink url="http://config.privoxy.org/toggle">web-based toggle
    feature</ulink> may be used
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Type of value:</term>
  <listitem>
   <para>0 or 1</para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Default value:</term>
  <listitem>
   <para>1</para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Effect if unset:</term>
  <listitem>
   <para>
    The web-based toggle feature is disabled.
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Notes:</term>
  <listitem>
   <para>
    When toggled off, <application>Privoxy</application> acts like a normal,
    content-neutral proxy, i.e. it acts as if none of the actions applied to
    any URL.
   </para>
   <para>
    For the time being, access to the toggle feature can <emphasis>not</emphasis> be
    controlled separately by <quote>ACLs</quote> or HTTP authentication,
    so that everybody who can access <application>Privoxy</application> (see
    <quote>ACLs</quote> and <literal>listen-address</literal> above) can
    toggle it for all users. So this option is <emphasis>not recommended</emphasis>
    for multi-user environments with untrusted users.
   </para>
   <para>
    Note that you must have compiled <application>Privoxy</application> with
    support for this feature, otherwise this option has no effect. 
   </para>
  </listitem>
 </varlistentry>
</variablelist>
</sect4>


<sect4 id="enable-edit-actions"><title>enable-edit-actions</title>
<variablelist>
 <varlistentry>
  <term>Specifies:</term>
  <listitem>
   <para>
    Whether or not the <ulink url="http://config.privoxy.org/show-status">web-based actions
    file editor</ulink> may be used
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Type of value:</term>
  <listitem>
   <para>0 or 1</para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Default value:</term>
  <listitem>
   <para>1</para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Effect if unset:</term>
  <listitem>
   <para>
    The web-based actions file editor is disabled.
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Notes:</term>
  <listitem>
   <para>
    For the time being, access to the editor can <emphasis>not</emphasis> be
    controlled separately by <quote>ACLs</quote> or HTTP authentication,
    so that everybody who can access <application>Privoxy</application> (see
    <quote>ACLs</quote> and <literal>listen-address</literal> above) can
    modify its configuration for all users. So this option is <emphasis>not
    recommended</emphasis> for multi-user environments with untrusted users.
   </para>
   <para>
    Note that you must have compiled <application>Privoxy</application> with
    support for this feature, otherwise this option has no effect. 
   </para>
  </listitem>
 </varlistentry>
</variablelist>
</sect4>

<sect4 id="acls"><title>
<anchor id="permit-acces">
<anchor id="deny-acces">
ACLs: permit-access and deny-access</title>

<variablelist>
 <varlistentry>
  <term>Specifies:</term>
  <listitem>
   <para>
    Who can access what.
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Type of value:</term>
  <listitem>
   <para>
    <replaceable class="parameter">src_addr</replaceable>[/<replaceable class="parameter">src_masklen</replaceable>]
    [<replaceable class="parameter">dst_addr</replaceable>[/<replaceable class="parameter">dst_masklen</replaceable>]]
   </para>
   <para>
    Where <replaceable class="parameter">src_addr</replaceable> and 
   <replaceable class="parameter">dst_addr</replaceable> are IP addresses in dotted decimal notation or valid
    DNS names, and <replaceable class="parameter">src_masklen</replaceable> and
    <replaceable class="parameter">dst_masklen</replaceable> are subnet masks in CIDR notation, i.e. integer
    values from 2 to 30 representing the length (in bits) of the network address. The masks and the whole
    destination part are optional.
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Default value:</term>
  <listitem>
   <para><emphasis>Unset</emphasis></para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Effect if unset:</term>
  <listitem>
   <para>
    Don't restrict access further than implied by <literal>listen-address</literal>
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Notes:</term>
  <listitem>
   <para>
    Access controls are included at the request of ISPs and systems
    administrators, and <emphasis>are not usually needed by individual users</emphasis>.
    For a typical home user, it will normally suffice to ensure that 
    <application>Privoxy</application> only listens on the localhost or internal (home)
    network address by means of the <literal>listen-address</literal> option.
   </para>
   <para>
    Please see the warnings in the FAQ that this proxy is not intended to be a substitute
    for a firewall or to encourage anyone to defer addressing basic security
    weaknesses.
   </para>
   <para>
    Multiple ACL lines are OK.
    If any ACLs are specified, then the <application>Privoxy</application>
    talks only to IP addresses that match at least one <literal>permit-access</literal> line
    and don't match any subsequent <literal>deny-access</literal> line. In other words, the
    last match wins, with the default being <literal>deny-access</literal>.
   </para>
   <para>
    If <application>Privoxy</application> is using a forwarder (see <literal>forward</literal> below)
    for a particular destination URL, the <replaceable class="parameter">dst_addr</replaceable>
    that is examined is the address of the forwarder and <emphasis>NOT</emphasis> the address
    of the ultimate target. This is necessary because it may be impossible for the local
    <application>Privoxy</application> to determine the IP address of the
    ultimate target (that's often what gateways are used for).
   </para>
   <para>
    You should prefer using IP addresses over DNS names, because the address lookups take
    time. All DNS names must resolve! You can <emphasis>not</emphasis> use domain patterns
    like <quote>*.org</quote> or partial domain names. If a DNS name resolves to multiple
    IP addresses, only the first one is used.
   </para>
   <para>
    Denying access to particular sites by ACL may have undesired side effects
    if the site in question is hosted on a machine which also hosts other sites.
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Examples:</term>
  <listitem>
   <para>
    Explicitly define the default behavior if no ACL and
    <literal>listen-address</literal> are set: <quote>localhost</quote>
    is OK. The absence of a <replaceable class="parameter">dst_addr</replaceable> implies that
    <emphasis>all</emphasis> destination addresses are OK:
   </para>
   <para>
    <screen>
  permit-access  localhost
</screen>
   </para>
   <para>
    Allow any host on the same class C subnet as www.privoxy.org access to
    nothing but www.example.com:
   </para>
   <para>
    <screen>
  permit-access  www.privoxy.org/24 www.example.com/32
</screen>
   </para>
   <para>
    Allow access from any host on the 26-bit subnet 192.168.45.64 to anywhere,
    with the exception that 192.168.45.73 may not access www.dirty-stuff.example.com:
   </para>
   <para>
    <screen>
  permit-access  192.168.45.64/26
  deny-access    192.168.45.73    www.dirty-stuff.example.com
</screen>
   </para>
  </listitem>
 </varlistentry>
</variablelist>
</sect4>

<sect4 id="buffer-limit"><title>buffer-limit</title>

<variablelist>
 <varlistentry>
  <term>Specifies:</term>
  <listitem>
   <para>
    Maximum size of the buffer for content filtering.
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Type of value:</term>
  <listitem>
   <para>Size in Kbytes</para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Default value:</term>
  <listitem>
   <para>4096</para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Effect if unset:</term>
  <listitem>
   <para>
    Use a 4MB (4096 KB) limit.
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Notes:</term>
  <listitem>
   <para>
    For content filtering, i.e. the <literal>+filter</literal> and
    <literal>+deanimate-gif</literal> actions, it is necessary that 
    <application>Privoxy</application> buffers the entire document body.
    This can be potentially dangerous, since a server could just keep sending
    data indefinitely and wait for your RAM to exhaust -- with nasty consequences.
    Hence this option.
   </para>
   <para>
    When a document buffer size reaches the <literal>buffer-limit</literal>, it is
    flushed to the client unfiltered and no further attempt to
    filter the rest of the document is made. Remember that there may be multiple threads
    running, which might require up to <literal>buffer-limit</literal> Kbytes
    <emphasis>each</emphasis>, unless you have enabled <quote>single-threaded</quote>
    above.
   </para>
  </listitem>
 </varlistentry>
</variablelist>
</sect4>

</sect3>

<!--  ~  End section  ~  -->


<!--   ~~~~~       New section      ~~~~~     -->

<sect3 id="forwarding">
<title>Forwarding</title>

<para>
 This feature allows routing of HTTP requests through a chain of
 multiple proxies.
 It can be used to better protect privacy and confidentiality when
 accessing specific domains by routing requests to those domains
 through an anonymous public proxy (see e.g. <ulink
 url="http://www.multiproxy.org/anon_list.htm">http://www.multiproxy.org/anon_list.htm</ulink>)
 Or to use a caching proxy to speed up browsing. Or chaining to a parent
 proxy may be necessary because the machine that <application>Privoxy</application>
 runs on has no direct Internet access.
</para>

<para>
 Also specified here are SOCKS proxies. <application>Privoxy</application>
 supports the SOCKS 4 and SOCKS 4A protocols.
</para>

<sect4 id="forward"><title>forward</title>
<variablelist>
 <varlistentry>
  <term>Specifies:</term>
  <listitem>
   <para>
    To which parent HTTP proxy specific requests should be routed.
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Type of value:</term>
  <listitem>
   <para>
    <replaceable class="parameter">target_domain</replaceable>[:<replaceable class="parameter">port</replaceable>]
    <replaceable class="parameter">http_parent</replaceable>[/<replaceable class="parameter">port</replaceable>]
   </para>
   <para>
    Where <replaceable class="parameter">target_domain</replaceable> is a domain name pattern (see the
    chapter on domain matching in the <filename>default.action</filename> file),
    <replaceable class="parameter">http_parent</replaceable> is the address of the parent HTTP proxy
    as an IP addresses in dotted decimal notation or as a valid DNS name (or <quote>.</quote> to denote
    <quote>no forwarding</quote>, and the optional 
    <replaceable class="parameter">port</replaceable> parameters are TCP ports, i.e. integer
    values from 1 to 64535
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Default value:</term>
  <listitem>
   <para><emphasis>Unset</emphasis></para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Effect if unset:</term>
  <listitem>
   <para>
    Don't use parent HTTP proxies.
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Notes:</term>
  <listitem>
   <para>
    If <replaceable class="parameter">http_parent</replaceable> is <quote>.</quote>, then requests are not
    forwarded to another HTTP proxy but are made directly to the web servers.
   </para>
   <para>
    Multiple lines are OK, they are checked in sequence, and the last match wins.
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Examples:</term>
  <listitem>
   <para>
    Everything goes to an example anonymizing proxy, except SSL on port 443 (which it doesn't handle):
   </para>
   <para>
    <screen>
  forward   .*     anon-proxy.example.org:8080
  forward   :443   .
</screen>
   </para>
   <para>
    Everything goes to our example ISP's caching proxy, except for requests
    to that ISP's sites:
   </para>
   <para>
    <screen>
  forward   .*.                caching-proxy.example-isp.net:8000
  forward   .example-isp.net   .
</screen>
   </para>
  </listitem>
 </varlistentry>
</variablelist>
</sect4>

<sect4 id="socks"><title>
<anchor id="forward-socks4">
<anchor id="forward-socks4a">
forward-socks4 and forward-socks4a</title>

<variablelist>
 <varlistentry>
  <term>Specifies:</term>
  <listitem>
   <para>
    Through which SOCKS proxy (and to which parent HTTP proxy) specific requests should be routed.
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Type of value:</term>
  <listitem>
   <para>
    <replaceable class="parameter">target_domain</replaceable>[:<replaceable class="parameter">port</replaceable>]
    <replaceable class="parameter">socks_proxy</replaceable>[/<replaceable class="parameter">port</replaceable>]
    <replaceable class="parameter">http_parent</replaceable>[/<replaceable class="parameter">port</replaceable>]
   </para>
   <para>
    Where <replaceable class="parameter">target_domain</replaceable> is a domain name pattern (see the
    chapter on domain matching in the <filename>default.action</filename> file),
    <replaceable class="parameter">http_parent</replaceable> and <replaceable class="parameter">socks_proxy</replaceable>
    are IP addresses in dotted decimal notation or valid DNS names (<replaceable class="parameter">http_parent</replaceable>
    may be <quote>.</quote> to denote <quote>no HTTP forwarding</quote>), and the optional 
    <replaceable class="parameter">port</replaceable> parameters are TCP ports, i.e. integer values from 1 to 64535
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Default value:</term>
  <listitem>
   <para><emphasis>Unset</emphasis></para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Effect if unset:</term>
  <listitem>
   <para>
    Don't use SOCKS proxies.
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Notes:</term>
  <listitem>
   <para>
    Multiple lines are OK, they are checked in sequence, and the last match wins.
   </para>
   <para>
    The difference between <literal>forward-socks4</literal> and <literal>forward-socks4a</literal>
    is that in the SOCKS 4A protocol, the DNS resolution of the target hostname happens on the SOCKS
    server, while in SOCKS 4 it happens locally.
   </para>
   <para>
    If <replaceable class="parameter">http_parent</replaceable> is <quote>.</quote>, then requests are not
    forwarded to another HTTP proxy but are made (HTTP-wise) directly to the web servers, albeit through
    a SOCKS proxy.
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Examples:</term>
  <listitem>
   <para>
     From the company example.com, direct connections are made to all
     <quote>internal</quote> domains, but everything outbound goes through
     their ISP's proxy by way of example.com's corporate SOCKS 4A gateway to
     the Internet.
   </para>
   <para>
    <screen>
  forward-socks4a   .*.            socks-gw.example.com:1080  www-cache.example-isp.net:8080
  forward           .example.com   .
</screen>
   </para>
   <para>
    A rule that uses a SOCKS 4 gateway for all destinations but no HTTP parent looks like this:
   </para>
   <para>
    <screen>
  forward-socks4   .*.            socks-gw.example.com:1080  .
</screen>
   </para>
  </listitem>
 </varlistentry>
</variablelist>
</sect4>

<sect4 id="advanced-forwarding-examples"><title>Advanced Forwarding Examples</title>

<para>
 If you have links to multiple ISPs that provide various special content 
 only to their subscribers, you can configure multiple <application>Privoxies</application>
 which have connections to the respective ISPs to act as forwarders to each other, so that
 <emphasis>your</emphasis> users can see the internal content of all ISPs.
</para>

<para>
 Assume that host-a has a PPP connection to isp-a.net. And host-b has a PPP connection to
 isp-b.net. Both run <application>Privoxy</application>. Their forwarding
 configuration can look like this:
</para>

<para>
 host-a:
</para>

<para>
 <screen>
  forward    .*.         .
  forward    .isp-b.net  host-b:8118
</screen>
</para>

<para>
 host-b:
</para>

<para>
 <screen>
  forward    .*.         .
  forward    .isp-a.net  host-a:8118
</screen>
</para>

<para>
 Now, your users can set their browser's proxy to use either
 host-a or host-b and be able to browse the internal content
 of both isp-a and isp-b.
</para>

<para>
 If you intend to chain <application>Privoxy</application> and 
 <application>squid</application> locally, then chain as 
 <literal>browser -> squid -> privoxy</literal> is the recommended way. 
</para>

<para>
 Assuming that <application>Privoxy</application> and <application>squid</application>
 run on the same box, your squid configuration could then look like this:
</para>

<para>
 <screen>
  # Define Privoxy as parent proxy (without ICP) 
  cache_peer 127.0.0.1 parent 8118 7 no-query 

  # Define ACL for protocol FTP 
  acl ftp proto FTP 

  # Do not forward FTP requests to Privoxy
  always_direct allow ftp 

  # Forward all the rest to Privoxy
  never_direct allow all</screen>
</para>

<para>
 You would then need to change your browser's proxy settings to <application>squid</application>'s address and port.
 Squid normally uses port 3128. If unsure consult <literal>http_port</literal> in <filename>squid.conf</filename>.
</para>

</sect4>

</sect3>

<!--  ~  End section  ~  -->


<!--   ~~~~~       New section      ~~~~~     -->

<sect3 id="windows-gui">
<title>Windows GUI Options</title>
<para>
 <application>Privoxy</application> has a number of options specific to the
 Windows GUI interface:
</para>

<anchor id="activity-animation">
<para>
 If <quote>activity-animation</quote> is set to 1, the
 <application>Privoxy</application> icon will animate when
 <quote>Privoxy</quote> is active. To turn off, set to 0.
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
  <emphasis>activity-animation   1</emphasis>
   </literallayout>
  </msgtext> 
 </literal>
</para>

<anchor id="log-messages">
<para>
 If <quote>log-messages</quote> is set to 1,
 <application>Privoxy</application> will log messages to the console
 window:
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
  <emphasis>log-messages       1</emphasis>
   </literallayout>
  </msgtext> 
 </literal>
</para>

<anchor id="log-buffer-size">
<para> 
 If <quote>log-buffer-size</quote> is set to 1, the size of the log buffer,
 i.e. the amount of memory used for the log messages displayed in the
 console window, will be limited to <quote>log-max-lines</quote> (see below).
</para>

<para>
 Warning: Setting this to 0 will result in the buffer to grow infinitely and
 eat up all your memory!
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
  <emphasis>log-buffer-size      1</emphasis>
   </literallayout>
  </msgtext> 
 </literal>
</para>

<anchor id="log-max-lines">
<para>
 <application>log-max-lines</application> is the maximum number of lines held
 in the log buffer. See above.
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
  <emphasis>log-max-lines      200</emphasis>
   </literallayout>
  </msgtext> 
 </literal>
</para>

<anchor id="log-highlight-messages">
<para>
 If <quote>log-highlight-messages</quote> is set to 1,
 <application>Privoxy</application> will highlight portions of the log
 messages with a bold-faced font:
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
  <emphasis>log-highlight-messages   1</emphasis>
   </literallayout>
  </msgtext> 
 </literal>
</para>

<anchor id="log-font-name">
<para>
 The font used in the console window:
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
  <emphasis>log-font-name        Comic Sans MS</emphasis>
   </literallayout>
  </msgtext> 
 </literal>
</para>

<anchor id="log-font-size">
<para>
 Font size used in the console window:
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
  <emphasis>log-font-size        8</emphasis>
   </literallayout>
  </msgtext> 
 </literal>
</para>

<anchor id="show-on-task-bar">
<para>  
 <quote>show-on-task-bar</quote> controls whether or not
 <application>Privoxy</application> will appear as a button on the Task bar
 when minimized:
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
  <emphasis>show-on-task-bar     0</emphasis>
   </literallayout>
  </msgtext> 
 </literal>
</para>

<anchor id="close-button-minimizes">
<para>
 If <quote>close-button-minimizes</quote> is set to 1, the Windows close
 button will minimize <application>Privoxy</application> instead of closing
 the program (close with the exit option on the File menu).
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
  <emphasis>close-button-minimizes  1</emphasis>
   </literallayout>
  </msgtext> 
 </literal>
</para>

<anchor id="hide-console">
<para>
 The <quote>hide-console</quote> option is specific to the MS-Win console
 version of <application>Privoxy</application>. If this option is used,
 <application>Privoxy</application> will disconnect from and hide  the
 command console.
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
  #hide-console
   </literallayout>
  </msgtext> 
 </literal>
</para>

</sect3>
</sect2>

<!--  ~  End section  ~  -->


<!--   ~~~~~       New section      ~~~~~     -->
<sect2 id="actions-file"><title>Actions Files</title>

<para>
 The actions files are used to define what actions
 <application>Privoxy</application> takes for which URLs, and thus determines
 how ad images, cookies and various other aspects of HTTP content and
 transactions are handled, and on which sites (or even parts thereof). There 
 are three such files included with <application>Privoxy</application>, 
 with slightly different purposes. <filename>default.action</filename> sets
 the default policies. <filename>standard.action</filename> is used by 
 <application>Privoxy</application> and the web based editor to set 
 pre-defined values (and normally should not be edited). Local exceptions 
 are best done in <filename>user.action</filename>. The content of these 
 can all be viewed and edited from <ulink
 url="http://config.privoxy.org/show-status">http://config.privoxy.org/show-status</ulink>.
 </para>

<para> 
 Anything you want can blocked, including ads, banners, or just some obnoxious
 URL that you would rather not see is done here. Cookies can be accepted or rejected, or
 accepted only during the current browser session (i.e. not written to disk),
 content can be modified, JavaScripts tamed, user-tracking fooled, and much more.
 See below for a complete list of available actions.
</para>

<para>
 An actions file typically has sections. Near the top, <quote>aliases</quote> are 
 optionally defined (discussed <ulink
 url="configuration.html#ALIASES">below</ulink>), then the default set of rules
 which will apply universally to all sites and pages. And then below that,
 exceptions to the defined universal policies. 
</para>

<!--   ~~~~~       New section      ~~~~~     -->
<sect3>
<title>Finding the Right Mix</title>
<para>
 Note that some <link linkend="actions">actions</link> like cookie suppression
 or script disabling may render some sites unusable, which rely on these
 techniques to work properly. Finding the right mix of actions is not easy and
 certainly a matter of personal taste. In general, it can be said that the more
 <quote>aggressive</quote> your default settings (in the top section of the
 actions file) are, the more exceptions for <quote>trusted</quote> sites you
 will have to make later. If, for example, you want to kill popup windows per
 default, you'll have to make exceptions from that rule for sites that you
 regularly use and that require popups for actually useful content, like maybe
 your bank, favorite shop, or newspaper.
</para>

<para>
 We have tried to provide you with reasonable rules to start from in the
 distribution actions files. But there is no general rule of thumb on these
 things. There just are too many variables, and sites are constantly changing.
 Sooner or later you will want to change the rules (and read this chapter again :).
</para>
</sect3>

<!--   ~~~~~       New section      ~~~~~     -->
<sect3>
<title>How to Edit</title>
<para>
 The easiest way to edit the <quote>actions</quote> files is with a browser by
 using our browser-based editor, which can be reached from <ulink
 url="http://config.privoxy.org/show-status">http://config.privoxy.org/show-status</ulink>.
</para>

<para>
 If you prefer plain text editing to GUIs, you can of course also directly edit the
 the actions files.
</para>
</sect3>


<sect3>
<title>How Actions are Applied to URLs</title>
<para>
 Actions files are divided into sections. There are special sections,
 like the <quote><link linkend="aliases">alias</link></quote> sections which will be discussed later. For now
 let's concentrate on regular sections: They have a heading line (often split
 up to multiple lines for readability) which consist of a list of actions,
 separated by whitespace and enclosed in curly braces. Below that, there
 is a list of URL patterns, each on a separate line.
</para>

<para>
 To determine which actions apply to a request, the URL of the request is
 compared to all patterns in this file. Every time it matches, the list of
 applicable actions for the URL is incrementally updated, using the heading
 of the section in which the pattern is located. If multiple matches for
 the same URL set the same action differently, the last match wins. If not, 
 the effects are aggregated (e.g. a URL might match both the 
 <ulink url="configuration.html#HANDLE-AS-IMAGE"><quote>+handle-as-image</quote></ulink>
 and <ulink url="configuration.html#BLOCK"><quote>+block</quote></ulink> actions).
 
</para>

<para>
 You can trace this process by visiting <ulink
 url="http://config.privoxy.org/show-url-info">http://config.privoxy.org/show-url-info</ulink>.
</para>

<para>
 More detail on this is provided in the Appendix, <link linkend="ACTIONSANAT">
 Anatomy of an Action</link>.
</para>
</sect3>

<!--   ~~~~~       New section      ~~~~~     -->
<sect3>
<title>Patterns</title>
<para>
 Generally, a pattern has the form <literal>&lt;domain&gt;/&lt;path&gt;</literal>,
 where both the <literal>&lt;domain&gt;</literal> and <literal>&lt;path&gt;</literal>
 are optional. (This is why the pattern <literal>/</literal> matches all URLs).
</para>

<variablelist>
 <varlistentry>
  <term><literal>www.example.com/</literal></term>
  <listitem>
   <para>
    is a domain-only pattern and will match any request to <literal>www.example.com</literal>,
    regardless of which document on that server is requested.
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term><literal>www.example.com</literal></term>
  <listitem>
   <para>
    means exactly the same. For domain-only patterns, the trailing <literal>/</literal> may
    be omitted.
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term><literal>www.example.com/index.html</literal></term>
  <listitem>
   <para>
    matches only the single document <literal>/index.html</literal>
    on <literal>www.example.com</literal>.
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term><literal>/index.html</literal></term>
  <listitem>
   <para>
    matches the document <literal>/index.html</literal>, regardless of the domain,
    i.e. on <emphasis>any</emphasis> web server.
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term><literal>index.html</literal></term>
  <listitem>
   <para>
    matches nothing, since it would be  interpreted as a domain name and
    there is no top-level domain called <literal>.html</literal>.
   </para>
  </listitem>
 </varlistentry>
</variablelist>

<sect4><title>The Domain Pattern</title>

<para>
 The matching of the domain part offers some flexible options: if the
 domain starts or ends with a dot, it becomes unanchored at that end. 
 For example:
</para>

<variablelist>
 <varlistentry>
  <term><literal>.example.com</literal></term>
  <listitem>
   <para>
    matches any domain that <emphasis>ENDS</emphasis> in
    <literal>.example.com</literal>
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term><literal>www.</literal></term>
  <listitem>
   <para>
    matches any domain that <emphasis>STARTS</emphasis> with
    <literal>www.</literal>
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term><literal>.example.</literal></term>
  <listitem>
   <para>
    matches any domain that <emphasis>CONTAINS</emphasis> <literal>.example.</literal>
    (Correctly speaking: It matches any FQDN that contains <literal>example</literal> as a domain.)
   </para>
  </listitem>
 </varlistentry>
</variablelist>

<para>
 Additionally, there are wild-cards that you can use in the domain names
 themselves. They work pretty similar to shell wild-cards: <quote>*</quote>
 stands for zero or more arbitrary characters, <quote>?</quote> stands for
 any single character, you can define character classes in square
 brackets and all of that can be freely mixed:
</para>

<variablelist>
 <varlistentry>
  <term><literal>ad*.example.com</literal></term>
  <listitem>
   <para>
    matches <quote>adserver.example.com</quote>, 
    <quote>ads.example.com</quote>, etc but not <quote>sfads.example.com</quote>
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term><literal>*ad*.example.com</literal></term>
  <listitem>
   <para>
    matches all of the above, and then some.
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term><literal>.?pix.com</literal></term>
  <listitem>
   <para>
    matches <literal>www.ipix.com</literal>,
    <literal>pictures.epix.com</literal>, <literal>a.b.c.d.e.upix.com</literal> etc. 
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term><literal>www[1-9a-ez].example.c*</literal></term>
  <listitem>
   <para>
     matches <literal>www1.example.com</literal>, 
     <literal>www4.example.cc</literal>, <literal>wwwd.example.cy</literal>, 
     <literal>wwwz.example.com</literal> etc., but <emphasis>not</emphasis> 
     <literal>wwww.example.com</literal>.
   </para>
  </listitem>
 </varlistentry>
</variablelist>

</sect4>

<sect4><title>The Path Pattern</title>

<para>
 <application>Privoxy</application> uses Perl compatible regular expressions
 (through the <ulink url="http://www.pcre.org/">PCRE</ulink> library) for
 matching the path.
</para>

<para>
 There is an <link linkend="regex">Appendix</link> with a brief quick-start into regular
 expressions, and full (very technical) documentation on PCRE regex syntax is available on-line
 at <ulink url="http://www.pcre.org/man.txt">http://www.pcre.org/man.txt</ulink>.
 You might also find the Perl man page on regular expressions (<literal>man perlre</literal>)
 useful, which is available on-line at <ulink
 url="http://www.perldoc.com/perl5.6/pod/perlre.html">http://www.perldoc.com/perl5.6/pod/perlre.html</ulink>.
</para>

<para>
 Note that the path pattern is automatically left-anchored at the <quote>/</quote>,
 i.e. it matches as if it would start with a <quote>^</quote> (regular expression speak 
 for the beginning of a line).
</para>

<para>
 Please also note that matching in the path is case
 <emphasis>INSENSITIVE</emphasis> by default, but you can switch to case
 sensitive at any point in the pattern by using the 
 <quote>(?-i)</quote> switch:
 <literal>www.example.com/(?-i)PaTtErN.*</literal> will match only
 documents whose path starts with <literal>PaTtErN</literal> in
 <emphasis>exactly</emphasis> this capitalization.
</para>
</sect4>

</sect3>

<!--  ~  End section  ~  -->


<!--   ~~~~~       New section      ~~~~~     -->

<sect3 id="actions">
<title>Actions</title>
<para>
 All actions are disabled by default, until they are explicitly enabled
 somewhere in an actions file. Actions are turned on if preceded with a
 <quote>+</quote>, and turned off if preceded with a <quote>-</quote>. So a
 <quote>+action</quote> means <quote>do that action</quote>, e.g.
 <quote>+block</quote> means please <quote>block the following URL
 patterns</quote>. 
</para>

<para> 
 Actions are invoked by enclosing the action name in curly braces (e.g.
 {+some_action}), followed by a list of URLs (or patterns that match URLs) to
 which the action applies. There are three classes of actions: 
</para>

<para>
 <itemizedlist>

 <listitem>
  <para>  
   Boolean, i.e the action can only be <quote>on</quote> or
   <quote>off</quote>. Examples: 
 </para>
  <para>
   <literal>
    <msgtext> 
     <literallayout>
  <emphasis>{+name}</emphasis>        # enable this action
  <emphasis>{-name}</emphasis>        # disable this action
     </literallayout>
    </msgtext> 
   </literal>
  </para>
 </listitem>


 <listitem>
  <para>  
   Parameterized, e.g. <quote>+/-hide-user-agent{ Mozilla 1.0 }</quote>, 
   where some value is required in order to enable this type of action.
   Examples:
  </para>
  <para>
   <literal>
    <msgtext> 
     <literallayout>
  <emphasis>{+name{param}}</emphasis>  # enable action and set parameter to <quote>param</quote>
  <emphasis>{-name}</emphasis>         # disable action (<quote>parameter</quote>) can be omitted
     </literallayout>
    </msgtext> 
   </literal>
  </para>
 </listitem>
 
 <listitem>
  <para>  
  <!-- oes, or someone, check this. Re-worded 04/20/02 HB. -->
   Multi-value, e.g. <quote>{+/-add-header{Name: value}}</quote> or
   <quote>{+/-send-wafer{name=value}}</quote>), where some value needs to be defined
   in addition to simply enabling the action. Examples:
  </para>
  <para>
   <literal>
    <msgtext> 
     <literallayout>
  <emphasis>{+name{param=value}}</emphasis>   # enable action and set <quote>param</quote> to <quote>value</quote>
  <emphasis>{-name{param=value}}</emphasis>   # remove the parameter <quote>param</quote> completely
  <emphasis>{-name}</emphasis>                # disable this action totally and remove <application>param</application> too
     </literallayout>
    </msgtext> 
   </literal>
  </para>
 </listitem>

 </itemizedlist>
</para>

<para>
 If nothing is specified in any actions file, no <quote>actions</quote> are
 taken. So in this case <application>Privoxy</application> would just be a
 normal, non-blocking, non-anonymizing proxy. You must specifically enable the
 privacy and blocking features you need (although the provided default actions
 files will give a good starting point).
</para>

<para>
 Later defined actions always over-ride earlier ones.  So exceptions 
 to any rules you make, should come in the latter part of the file. For
 multi-valued actions, the actions are applied in the order they are
 specified. Actions files are processed in the order they are defined 
 in <filename>config</filename> (the default installation has three 
 actions files). It also quite possible for any given URL pattern to 
 match more than one action!
</para>

<!-- start actions listing -->
<para>
 The list of valid <application>Privoxy</application> <quote>actions</quote> are:
</para>


<!-- ********************************************************** -->
<!-- Please note the below defined actions use id's that are    -->
<!-- probably linked from other places, so please don't change. -->
<!--                                                            -->
<!-- ********************************************************** -->


<!--   ~~~~~       New section      ~~~~~     -->

<sect4 id="add-header">
<title><emphasis>+add-header{Name: value}</emphasis></title>

<variablelist>
 <varlistentry>
  <term>Type:</term>
  <!-- boolean, parameterized, Multi-value -->
  <listitem>
   <para>Multi-value.</para>
  </listitem>
 </varlistentry>
 
 <varlistentry>
  <term>Typical uses:</term>
  <listitem>
   <para>
    Send a user defined HTTP header to the web server.
   </para>
  </listitem>
 </varlistentry>

 <varlistentry>
  <term>Possible values:</term>
  <listitem>
   <para>
    Any value is possible. Validity of the defined HTTP headers is not checked.
   </para>
  </listitem>
 </varlistentry>
 
 <varlistentry>
  <term>Example usage:</term>
  <listitem>
    <literallayout>
     <emphasis>{+add-header{X-User-Tracking: sucks}}</emphasis>
     <emphasis>.example.com</emphasis>
    </literallayout>
  </listitem>
 </varlistentry>

<varlistentry>
  <term>Notes:</term>
  <listitem>
   <para>
    This action may be specified multiple times, in order to define multiple 
    headers. This is rarely needed for the typical user. If you don't know what 
    <quote>HTTP headers</quote> are, you definitely don't need to worry about this 
    one.
   </para>
  </listitem>
 </varlistentry>
</variablelist>
</sect4>


<!--   ~~~~~       New section      ~~~~~     -->
<sect4 id="block">
<title><emphasis>+block</emphasis></title>

<variablelist>
 <varlistentry>
  <term>Type:</term>
  <!-- boolean, parameterized, Multi-value -->
  <listitem>
   <para>Boolean.</para>
  </listitem>
 </varlistentry>

 <varlistentry>
  <term>Typical uses:</term>
  <listitem>
   <para>
    Used to block a URL from reaching your browser. The URL may be 
    anything, but is typically used to block ads or other obnoxious 
    content.    
   </para>
  </listitem>
 </varlistentry>

 <varlistentry>
  <term>Possible values:</term>
  <listitem>
   <para>N/A</para>
  </listitem>
 </varlistentry>
 
 <varlistentry>
  <term>Example usage:</term>
  <listitem>
    <literallayout>
     <emphasis>{+block}</emphasis>
     <emphasis>.banners.example.com</emphasis>
     <emphasis>.ads.r.us</emphasis>
    </literallayout>
  </listitem>
 </varlistentry>

<varlistentry>
  <term>Notes:</term>
  <listitem>
   <para>
    If a URL matches one of the blocked patterns, <application>Privoxy</application>
    will intercept the URL and display its special <quote>BLOCKED</quote> page
    instead. If there is sufficient space, a large red banner will appear with
    a friendly message about why the page was blocked, and a way to go there
    anyway. If there is insufficient space a smaller blocked page will appear
    without the red banner. 
    <ulink url="http://ads.bannerserver.example.com/nasty-ads/sponsor.html">Click here</ulink>
    to view the default blocked HTML page (<application>Privoxy</application> must be running 
    for this to work as intended!).
   </para>

   <para> 
    A very important exception is if the URL <emphasis>matches both</emphasis>
    <quote>+block</quote> and <ulink
    url="configuration.html#HANDLE-AS-IMAGE"><quote>+handle-as-image</quote></ulink>,
    then it will be handled by 
    <ulink url="configuration.html#SET-IMAGE-BLOCKER"><quote>+set-image-blocker</quote></ulink>
    (see below). It is important to understand this process, in order 
    to understand how <application>Privoxy</application> is able to deal with 
    ads and other objectionable content.
   </para>
   <para>
    The <ulink url="configuration.html#FILTER"><quote>+filter</quote></ulink>
    action can also perform some of the 
    same functionality as <quote>+block</quote>, but by virtue of very 
    different programming techniques, and is most often used for different 
    reasons.
   </para>
  </listitem>
 </varlistentry>

</variablelist>
</sect4>


<!--   ~~~~~       New section      ~~~~~     -->
<sect4 id="deanimate-gifs">
<title><emphasis>+deanimate-gifs</emphasis></title>

<variablelist>
 <varlistentry>
  <term>Type:</term>
  <!-- boolean, parameterized, Multi-value -->
  <listitem>
   <para>Parameterized.</para>
  </listitem>
 </varlistentry>

 <varlistentry>
  <term>Typical uses:</term>
  <listitem>
   <para>
    To stop those annoying, distracting animated GIF images.
   </para>
  </listitem>
 </varlistentry>

 <varlistentry>
  <term>Possible values:</term>
  <listitem>
   <para>
    <quote>last</quote> or <quote>first</quote>
   </para>
  </listitem>
 </varlistentry>
 
 <varlistentry>
  <term>Example usage:</term>
  <listitem>
    <literallayout>
      <emphasis>{+deanimate-gifs{last}}</emphasis>
      <emphasis>.example.com</emphasis>
    </literallayout>
  </listitem>
 </varlistentry>

 <varlistentry>
  <term>Notes:</term>
  <listitem>
   <para>
    De-animate all animated GIF images, i.e. reduce them to their last frame.
    This will also shrink the images considerably (in bytes, not pixels!). If
    the option <quote>first</quote> is given, the first frame of the animation
    is used as the replacement. If <quote>last</quote> is given, the last
    frame of the animation is used instead, which probably makes more sense for
    most banner animations, but also has the risk of not showing the entire
    last frame (if it is only a delta to an earlier frame).
   </para>
  </listitem>
 </varlistentry>

</variablelist>
</sect4>

<!--   ~~~~~       New section      ~~~~~     -->
<sect4 id="downgrade-http-version">
<title><emphasis>+downgrade-http-version</emphasis></title>

<variablelist>
 <varlistentry>
  <term>Type:</term>
  <!-- boolean, parameterized, Multi-value -->
  <listitem>
   <para>Boolean.</para>
  </listitem>
 </varlistentry>

 <varlistentry>
  <term>Typical uses:</term>
  <listitem>
   <para>
    <quote>+downgrade-http-version</quote> will downgrade HTTP/1.1 client requests to
    HTTP/1.0 and downgrade the responses as well.
   </para>
  </listitem>
 </varlistentry>

 <varlistentry>
  <term>Possible values:</term>
  <listitem>
   <para>
    N/A
   </para>
  </listitem>
 </varlistentry>
 
 <varlistentry>
  <term>Example usage:</term>
  <listitem>
    <literallayout>
     <emphasis>{+downgrade-http-version}</emphasis>
     <emphasis>.example.com</emphasis>
    </literallayout>
  </listitem>
 </varlistentry>

 <varlistentry>
  <term>Notes:</term>
  <listitem>
   <para>
    Use this action for servers that use HTTP/1.1 protocol features that
    <application>Privoxy</application> doesn't handle well yet. HTTP/1.1 is
    only partially implemented. Default is not to downgrade requests. This is
    an infrequently needed action, and is used to help with rare problem sites only.
   </para>
  </listitem>
 </varlistentry>

</variablelist>
</sect4>

<!--   ~~~~~       New section      ~~~~~     -->
<sect4 id="fast-redirects">
<title><emphasis>+fast-redirects</emphasis></title>

<variablelist>
 <varlistentry>
  <term>Type:</term>
  <!-- boolean, parameterized, Multi-value -->
  <listitem>
   <para>Boolean.</para>
  </listitem>
 </varlistentry>

 <varlistentry>
  <term>Typical uses:</term>
  <listitem>
   <para>
    The <quote>+fast-redirects</quote> action enables interception of 
    <quote>redirect</quote> requests from one server to another, which 
    are used to track users.<application>Privoxy</application> can cut off
    all but the last valid URL in a redirect request and send a local redirect
    back to your browser without contacting the intermediate site(s).
   </para>
  </listitem>
 </varlistentry>

 <varlistentry>
  <term>Possible values:</term>
  <listitem>
   <para>
    N/A
   </para>
  </listitem>
 </varlistentry>
 
 <varlistentry>
  <term>Example usage:</term>
  <listitem>
    <literallayout>
     <emphasis>{+fast-redirects}</emphasis>
     <emphasis>.example.com</emphasis>
    </literallayout>
  </listitem>
 </varlistentry>

 <varlistentry>
  <term>Notes:</term>
  <listitem>
   <para>  
    Many sites, like yahoo.com, don't just link to other sites. Instead, they
    will link to some script on their own server, giving the destination as a
    parameter, which will then redirect you to the final target. URLs
    resulting from this scheme typically look like:
    <emphasis>http://some.place/some_script?http://some.where-else</emphasis>.
  </para>
   <para>
    Sometimes, there are even multiple consecutive redirects encoded in the
    URL. These redirections via scripts make your web browsing more traceable,
    since the server from which you follow such a link can see where you go
    to. Apart from that, valuable bandwidth and time is wasted, while your
    browser ask the server for one redirect after the other. Plus, it feeds
    the advertisers.
   </para>
   <para>
    This is a normally <quote>on</quote> feature, and often requires exceptions
    for sites that are sensitive to defeating this mechanism.
   </para>
  </listitem>
 </varlistentry>

</variablelist>
</sect4>


<!--   ~~~~~       New section      ~~~~~     -->
<sect4 id="filter">
<title><emphasis>+filter</emphasis></title>

<variablelist>
 <varlistentry>
  <term>Type:</term>
  <!-- boolean, parameterized, Multi-value -->
  <listitem>
   <para>Parameterized.</para>
  </listitem>
 </varlistentry>

 <varlistentry>
  <term>Typical uses:</term>
  <listitem>
   <para>
    Apply page filtering as defined by named sections of the
    <filename>default.filter</filename> file to the specified site(s). 
    <quote>Filtering</quote> can be any modification of the raw 
    page content, including re-writing or deletion of content.
   </para>
  </listitem>
 </varlistentry>

 <varlistentry>
  <term>Possible values:</term>
  <listitem>
   <para>
    <quote>+filter</quote> must include the name of one of the section identifiers
    from <filename>default.filter</filename> (or whatever
    <emphasis>filterfile</emphasis> is specified in <filename>config</filename>).
   </para>
  </listitem>
 </varlistentry>
 
 <varlistentry>
  <term>Example usage (from the current <filename>default.filter</filename>):</term>
  <listitem>
   <simplelist>
   <member>
    <emphasis>+filter{html-annoyances}</emphasis>:  Get rid of particularly annoying HTML abuse.
   </member>
  </simplelist>
  <simplelist>
   <member>
    <emphasis>+filter{js-annoyances}</emphasis>:    Get rid of particularly annoying JavaScript abuse
   </member>
  </simplelist>
  <simplelist>
   <member>
    <emphasis>+filter{content-cookies}</emphasis>:   Kill cookies that come in the HTML or JS content 
   </member>
  </simplelist>
  <simplelist>
   <member>
    <emphasis>+filter{popups}</emphasis>:         Kill all popups in JS and HTML
   </member>
  </simplelist>
  <simplelist>
   <member>
    <emphasis>+filter{frameset-borders}</emphasis>: Give frames a border and make them resizable 
   </member>
  </simplelist>
  <simplelist>
   <member>
    <emphasis>+filter{webbugs}</emphasis>:          Squish WebBugs (1x1 invisible GIFs used for user tracking)
   </member>
  </simplelist>
  <simplelist>
   <member>
    <emphasis>+filter{refresh-tags}</emphasis>:     Kill automatic refresh tags (for dial-on-demand setups) 
   </member>
  </simplelist>
  <simplelist>
   <member>
    <emphasis>+filter{fun}</emphasis>:              Text replacements  for subversive browsing fun!
   </member>
  </simplelist>
  <simplelist>
   <member>
    <emphasis>+filter{nimda}</emphasis>:            Remove Nimda (virus) code.
   </member>
  </simplelist>
  <simplelist>
   <member>
    <emphasis>+filter{banners-by-size}</emphasis>:  Kill banners by size (<emphasis>very</emphasis> efficient!)
   </member>
  </simplelist>
  <simplelist>
   <member>
    <emphasis>+filter{shockwave-flash}</emphasis>:   Kill embedded Shockwave Flash objects
   </member>
  </simplelist>
  <simplelist>
   <member>
    <emphasis>+filter{crude-parental}</emphasis>:   Kill all web pages that contain the words "sex" or "warez"
   </member>
  </simplelist>
  </listitem>
 </varlistentry>

 <varlistentry>
  <term>Notes:</term>
  <listitem>
   <para>
    This is potentially a very powerful feature! And requires a knowledge 
    of regular expressions if you want to <quote>roll your own</quote>.
    Filtering operates on a line by line basis throughout the entire page.
   </para>
   <para>
    Filtering requires buffering the page content, which may appear to
    slow down page rendering since nothing is displayed until all content has
    passed the filters. (It does not really take longer, but seems that way
    since the page is not incrementally displayed.) This effect will be more
    noticeable on slower connections.
   </para>
   <para>
    Filtering can achieve some of the effects as the 
    <ulink url="configuration.html#BLOCK"><quote>+block</quote></ulink>
    action, i.e. it can be used to block ads and banners. In the overall 
    scheme of things, filtering is one of the first things <quote>Privoxy</quote> 
    does with a web page. So other most other actions are applied to the 
    already <quote>filtered</quote> page.
   </para>
  </listitem>
 </varlistentry>

</variablelist>
</sect4>


<!--   ~~~~~       New section      ~~~~~     -->
<sect4 id="hide-forwarded-for-headers">
<title><emphasis>+hide-forwarded-for-headers</emphasis></title>

<variablelist>
 <varlistentry>
  <term>Type:</term>
  <!-- Boolean, Parameterized, Multi-value -->
  <listitem>
   <para>Boolean.</para>
  </listitem>
 </varlistentry>

 <varlistentry>
  <term>Typical uses:</term>
  <listitem>
   <para>
    Block any existing X-Forwarded-for HTTP header, and do not add a new one.
   </para>
  </listitem>
 </varlistentry>

 <varlistentry>
  <term>Possible values:</term>
  <listitem>
   <para>
    N/A
   </para>
  </listitem>
 </varlistentry>
 
 <varlistentry>
  <term>Example usage:</term>
  <listitem>
    <literallayout>
     <emphasis>{+hide-forwarded-for-headers}</emphasis>
     <emphasis>.example.com</emphasis>
    </literallayout>
  </listitem>
 </varlistentry>

 <varlistentry>
  <term>Notes:</term>
  <listitem>
   <para>
    It is fairly safe to leave this on. It does not seem to break many sites.
   </para>
  </listitem>
 </varlistentry>

</variablelist>
</sect4>


<!--   ~~~~~       New section      ~~~~~     -->
<sect4 id="hide-from-header">
<title><emphasis>+hide-from-header</emphasis></title>

<variablelist>
 <varlistentry>
  <term>Type:</term>
  <!-- Boolean, Parameterized, Multi-value -->
  <listitem>
   <para>Parameterized.</para>
  </listitem>
 </varlistentry>

 <varlistentry>
  <term>Typical uses:</term>
  <listitem>
   <para>
    To block the browser from sending your email address in a <quote>From:</quote>
    header.
   </para>
  </listitem>
 </varlistentry>

 <varlistentry>
  <term>Possible values:</term>
  <listitem>
   <para>
    Keyword: <quote>block</quote>, or any user defined value.
   </para>
  </listitem>
 </varlistentry>
 
 <varlistentry>
  <term>Example usage:</term>
  <listitem>
    <literallayout>
     <emphasis>{+hide-from-header{block}}</emphasis>
     <emphasis>.example.com</emphasis>
    </literallayout>
  </listitem>
 </varlistentry>

 <varlistentry>
  <term>Notes:</term>
  <listitem>
   <para>
    The keyword <quote>block</quote> will completely remove the header 
    (not to be confused with the <ulink
    url="configuration.html#BLOCK"><quote>+block</quote></ulink> action).
    Alternately, you can specify any value you prefer to send to the web
    server.
   </para>
  </listitem>
 </varlistentry>

</variablelist>
</sect4>


<!--   ~~~~~       New section      ~~~~~     -->
<sect4 id="hide-referer">
<title><emphasis><anchor id="hide-referrer">+hide-referer</emphasis></title>


<variablelist>
 <varlistentry>
  <term>Type:</term>
  <!-- Boolean, Parameterized, Multi-value -->
  <listitem>
   <para>Parameterized.</para>
  </listitem>
 </varlistentry>

 <varlistentry>
  <term>Typical uses:</term>
  <listitem>
   <para>
     Don't send the <quote>Referer:</quote> (sic) HTTP header to the web site.
     Or, alternately send a forged header instead.
   </para>
  </listitem>
 </varlistentry>

 <varlistentry>
  <term>Possible values:</term>
  <listitem>
   <para>
     Prevent the header from being sent with the keyword, <quote>block</quote>.
     Or, <quote>forge</quote> a URL to one from the same server as the request.
     Or, set to user defined value of your choice.
   </para>
  </listitem>
 </varlistentry>
 
 <varlistentry>
  <term>Example usage:</term>
  <listitem>
    <literallayout>
     <emphasis>{+hide-referer{forge}}</emphasis>
     <emphasis>.example.com</emphasis>
    </literallayout>
  </listitem>
 </varlistentry>

 <varlistentry>
  <term>Notes:</term>
  <listitem>
   <para>
    <quote>forge</quote> is the preferred option here, since some servers will
    not send images back otherwise.
   </para>
  <para>  
   <quote>+hide-referrer</quote> is an alternate spelling of
   <quote>+hide-referer</quote>. It has the exact same parameters, and can be freely
   mixed with, <quote>+hide-referer</quote>. (<quote>referrer</quote> is the
   correct English spelling, however the HTTP specification has a bug - it
   requires it to be spelled as <quote>referer</quote>.) 
  </para>
  </listitem>
 </varlistentry>

</variablelist>
</sect4>


<!--   ~~~~~       New section      ~~~~~     -->
<sect4 id="hide-user-agent">
<title><emphasis>+hide-user-agent</emphasis></title>

<variablelist>
 <varlistentry>
  <term>Type:</term>
  <!-- Boolean, Parameterized, Multi-value -->
  <listitem>
   <para>Parameterized.</para>
  </listitem>
 </varlistentry>

 <varlistentry>
  <term>Typical uses:</term>
  <listitem>
   <para>
    To change the <quote>User-Agent:</quote> header so web servers can't tell
    your browser type. Who's business is it anyway?
   </para>
  </listitem>
 </varlistentry>

 <varlistentry>
  <term>Possible values:</term>
  <listitem>
   <para>
    Any user defined string.
   </para>
  </listitem>
 </varlistentry>
 
 <varlistentry>
  <term>Example usage:</term>
  <listitem>
    <literallayout>
     <emphasis>{+hide-user-agent{Netscape 6.1 (X11; I; Linux 2.4.18 i686)}}</emphasis>
     <emphasis>.msn.com</emphasis>
    </literallayout>
  </listitem>
 </varlistentry>

 <varlistentry>
  <term>Notes:</term>
  <listitem>
   <para>
     Warning! This breaks many web sites that depend on this in order 
     to determine how the target browser will respond to various 
     requests. Use with caution.
   </para>
  </listitem>
 </varlistentry>

</variablelist>
</sect4>

<!--   ~~~~~       New section      ~~~~~     -->
<sect4 id="handle-as-image">
<title><emphasis>+handle-as-image</emphasis></title>

<variablelist>
 <varlistentry>
  <term>Type:</term>
  <!-- Boolean, Parameterized, Multi-value -->
  <listitem>
   <para>Boolean.</para>
  </listitem>
 </varlistentry>

 <varlistentry>
  <term>Typical uses:</term>
  <listitem>
   <para>
    To define what <application>Privoxy</application> should treat 
    automatically as an image, and is an important ingredient of how 
    ads are handled.
   </para>
  </listitem>
 </varlistentry>

 <varlistentry>
  <term>Possible values:</term>
  <listitem>
   <para>
    N/A
   </para>
  </listitem>
 </varlistentry>
 
 <varlistentry>
  <term>Example usage:</term>
  <listitem>
    <literallayout>
     <emphasis>{+handle-as-image}</emphasis>
     <emphasis>/.*\.(gif|jpg|jpeg|png|bmp|ico)</emphasis>
    </literallayout>
  </listitem>
 </varlistentry>

 <varlistentry>
  <term>Notes:</term>
  <listitem>
   <para>
    This only has meaning if the URL (or pattern) also is
    <quote>+block</quote>ed, in which case a user definable image can
    be sent rather than a HTML page. This is integral to the whole concept of
    ad blocking: the URL must match <emphasis>both</emphasis> a <ulink
    url="configuration.html#BLOCK"><quote>+block</quote></ulink> rule,
    <emphasis>and</emphasis> <quote>+handle-as-image</quote>.
    (See <ulink
    url="configuration.html#SET-IMAGE-BLOCKER"><quote>+set-image-blocker</quote></ulink>
    below for control over what will actually be displayed by the browser.)
   </para>
   <para>
    There is little reason to change the default definition for this action.
   </para>
  </listitem>
 </varlistentry>

</variablelist>
</sect4>


<!--   ~~~~~       New section      ~~~~~     -->
<sect4 id="set-image-blocker">
<title><emphasis>+set-image-blocker</emphasis></title>

<variablelist>
 <varlistentry>
  <term>Type:</term>
  <!-- Boolean, Parameterized, Multi-value -->
  <listitem>
   <para>Parameterized.</para>
  </listitem>
 </varlistentry>

 <varlistentry>
  <term>Typical uses:</term>
  <listitem>
   <para>
    Decide what to do with URLs that end up tagged with <emphasis>both</emphasis> 
    <ulink url="configuration.html#BLOCK"><quote>+block</quote></ulink>
    and <ulink
    url="configuration.html#HANDLE-AS-IMAGE"><quote>+handle-as-image</quote></ulink>,
    e.g an advertisement.
   </para>
  </listitem>
 </varlistentry>

 <varlistentry>
  <term>Possible values:</term>
  <listitem>
   <para>
    There are four available options: <quote>-set-image-blocker</quote> will send a HTML
    <quote>blocked</quote> page, usually resulting in a <quote>broken
    image</quote> icon.
    <quote>+set-image-blocker{<emphasis>blank</emphasis>}</quote> will send a
    1x1 transparent GIF image.
    <quote>+set-image-blocker{<emphasis>pattern</emphasis>}</quote> will send a
    checkerboard type pattern (the default). And finally,
    <quote>+set-image-blocker{<emphasis>http://xyz.com</emphasis>}</quote> will
    send a HTTP temporary redirect to the specified image. This has the
    advantage of the icon being being cached by the browser, which will speed
    up the display.
   </para>
  </listitem>
 </varlistentry>
 
 <varlistentry>
  <term>Example usage:</term>
  <listitem>
    <literallayout>
     <emphasis>{+set-image-blocker{blank}}</emphasis>
     <emphasis>.example.com</emphasis>
    </literallayout>
  </listitem>
 </varlistentry>

 <varlistentry>
  <term>Notes:</term>
  <listitem>
   <para>
    If you want <emphasis>invisible</emphasis> ads, they need to meet 
    criteria as matching both <emphasis>images</emphasis> and <emphasis>blocked</emphasis>
    actions. And then, <quote>image-blocker</quote> should be set to
    <quote>blank</quote> for invisibility. Note you cannot treat HTML pages as
    images in most cases. For instance, frames require an HTML page to
    display. So a frame that is an ad, typically cannot be treated as an image.
    Forcing an <quote>image</quote> in this situation just will not work
    reliably. 
   </para>
  </listitem>
 </varlistentry>

</variablelist>
</sect4>

<!--   ~~~~~       New section      ~~~~~     -->
<sect4 id="limit-connect">
<title><emphasis>+limit-connect</emphasis></title>

<variablelist>
 <varlistentry>
  <term>Type:</term>
  <!-- Boolean, Parameterized, Multi-value -->
  <listitem>
   <para>Parameterized.</para>
  </listitem>
 </varlistentry>

 <varlistentry>
  <term>Typical uses:</term>
  <listitem>
   <para>
    By default, <application>Privoxy</application> only allows HTTP CONNECT
    requests to port 443 (the standard, secure HTTPS port). Use 
    <quote>+limit-connect</quote> to disable this altogether, or to allow 
    more ports.
   </para>
  </listitem>
 </varlistentry>

 <varlistentry>
  <term>Possible values:</term>
  <listitem>
   <para>
    Any valid port number, or port number range.
   </para>
  </listitem>
 </varlistentry>
 
 <varlistentry>
  <term>Example usages:</term>
  <listitem>
   <!-- I had trouble getting the spacing to look right in my browser -->
   <!-- I probably have the wrong font setup, bollocks. -->
   <!-- Apparently the emphasis tag uses a proportional font no matter what -->
    <literallayout>
     <emphasis>+limit-connect{443}</emphasis>                       # This is the default and need not be specified.
     <emphasis>+limit-connect{80,443}</emphasis>                  # Ports 80 and 443 are OK.
     <emphasis>+limit-connect{-3, 7, 20-100, 500-}</emphasis>   # Port less than 3, 7, 20 to 100 and above 500 are OK.
    </literallayout>
  </listitem>
 </varlistentry>

 <varlistentry>
  <term>Notes:</term>
  <listitem>
   <para>
    The CONNECT methods exists in HTTP to allow access to secure websites
    (https:// URLs) through proxies. It works very simply: the proxy connects
    to the server on the specified port, and then short-circuits its
    connections to the client <emphasis>and</emphasis> to the remote proxy.
    This can be a big security hole, since CONNECT-enabled proxies can be
    abused as TCP relays very easily.
  </para>
  <para> 
   If you want to allow CONNECT for more ports than this, or want to forbid
   CONNECT altogether, you can specify a comma separated list of ports and
   port ranges (the latter using dashes, with the minimum defaulting to 0 and
   max to 65K).
  </para>
  <para>
   If you don't know what any of this means, there probably is no reason to 
   change this one.
  </para>
  </listitem>
 </varlistentry>

</variablelist>
</sect4>

<!--   ~~~~~       New section      ~~~~~     -->
<sect4 id="prevent-compression">
<title><emphasis>+prevent-compression</emphasis></title>

<variablelist>
 <varlistentry>
  <term>Type:</term>
  <!-- Boolean, Parameterized, Multi-value -->
  <listitem>
   <para>Boolean.</para>
  </listitem>
 </varlistentry>

 <varlistentry>
  <term>Typical uses:</term>
  <listitem>
   <para>
    Prevent the specified websites from compressing HTTP data.
   </para>
  </listitem>
 </varlistentry>

 <varlistentry>
  <term>Possible values:</term>
  <listitem>
   <para>
    N/A
   </para>
  </listitem>
 </varlistentry>
 
 <varlistentry>
  <term>Example usage:</term>
  <listitem>
    <literallayout>
     <emphasis>{+prevent-compression}</emphasis>
     <emphasis>.example.com</emphasis>
    </literallayout>
  </listitem>
 </varlistentry>

 <varlistentry>
  <term>Notes:</term>
  <listitem>
   <para>
    Some websites do this, which can be a problem for
    <application>Privoxy</application>, since 
    <ulink url="configuration.html#FILTER"><quote>+filter</quote></ulink>,
    <ulink url="configuration.html#KILL-POPUPS"><quote>+kill-popups</quote></ulink>
    and <ulink
    url="configuration.html#GIF-DEANIMATE"><quote>+gif-deanimate</quote></ulink>
    will not work on compressed data. This will slow down connections to those
    websites, though. Default typically is to turn
    <quote>prevent-compression</quote> on.
   </para>
  </listitem>
 </varlistentry>

</variablelist>
</sect4>

<!--   ~~~~~       New section      ~~~~~     -->
<sect4 id="session-cookies-only">
<title><emphasis>+session-cookies-only</emphasis></title>

<variablelist>
 <varlistentry>
  <term>Type:</term>
  <!-- Boolean, Parameterized, Multi-value -->
  <listitem>
   <para>Boolean.</para>
  </listitem>
 </varlistentry>

 <varlistentry>
  <term>Typical uses:</term>
  <listitem>
   <para>
    Allow cookies for the current browser session <emphasis>only</emphasis>.
   </para>
  </listitem>
 </varlistentry>

 <varlistentry>
  <term>Possible values:</term>
  <listitem>
   <para>
    N/A
   </para>
  </listitem>
 </varlistentry>
 
 <varlistentry>
  <term>Example usage (disabling):</term>
  <listitem>
    <literallayout>
     <emphasis>{-session-cookies-only}</emphasis>
     <emphasis>.example.com</emphasis>
    </literallayout>
  </listitem>
 </varlistentry>

 <varlistentry>
  <term>Notes:</term>
  <listitem>
   <para>
    If websites set cookies, <quote>+session-cookies-only</quote> will make sure
    they are erased when you exit and restart your web browser. 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.
   </para>
   <para>
    <quote>+prevent-*-cookies</quote> actions should be turned off as well (see
    below), for <quote>+session-cookies-only</quote> to work. Or, else no cookies 
    will get through at all. For, <quote>persistent</quote> cookies that survive 
    across browser sessions, see below as well.
   </para>
  </listitem>
 </varlistentry>

</variablelist>
</sect4>


<!--   ~~~~~       New section      ~~~~~     -->
<sect4 id="prevent-reading-cookies">
<title><emphasis>+prevent-reading-cookies</emphasis></title>

<variablelist>
 <varlistentry>
  <term>Type:</term>
  <!-- Boolean, Parameterized, Multi-value -->
  <listitem>
   <para>Boolean.</para>
  </listitem>
 </varlistentry>

 <varlistentry>
  <term>Typical uses:</term>
  <listitem>
   <para>
    Explicitly prevent the web server from reading any cookies on your 
    system.
   </para>
  </listitem>
 </varlistentry>

 <varlistentry>
  <term>Possible values:</term>
  <listitem>
   <para>
    N/A
   </para>
  </listitem>
 </varlistentry>
 
 <varlistentry>
  <term>Example usage:</term>
  <listitem>
    <literallayout>
     <emphasis>{+prevent-reading-cookies}</emphasis>
     <emphasis>.example.com</emphasis>
    </literallayout>
  </listitem>
 </varlistentry>

 <varlistentry>
  <term>Notes:</term>
  <listitem>
   <para>
    Often used in conjunction with <quote>+prevent-setting-cookies</quote> to 
    disable cookies completely. Note that 
    <ulink url="configuration.html#SESSION-COOKIES-ONLY"><quote>+session-cookies-only</quote></ulink>
    requires these to both be disabled (or else it never gets any cookies to cache).
   </para>
   <para>
    For <quote>persistent</quote> cookies to work (i.e. they survive across browser 
    sessions and reboots), all three cookie settings should be <quote>off</quote> 
    for the specified sites.
   </para>
  </listitem>
 </varlistentry>

</variablelist>
</sect4>


<!--   ~~~~~       New section      ~~~~~     -->
<sect4 id="prevent-setting-cookies">
<title><emphasis>+prevent-setting-cookies</emphasis></title>

<variablelist>
 <varlistentry>
  <term>Type:</term>
  <!-- Boolean, Parameterized, Multi-value -->
  <listitem>
   <para>Boolean.</para>
  </listitem>
 </varlistentry>

 <varlistentry>
  <term>Typical uses:</term>
  <listitem>
   <para>
    Explicitly block the web server from storing cookies on your 
    system.
   </para>
  </listitem>
 </varlistentry>

 <varlistentry>
  <term>Possible values:</term>
  <listitem>
   <para>
    N/A
   </para>
  </listitem>
 </varlistentry>
 
 <varlistentry>
  <term>Example usage:</term>
  <listitem>
    <literallayout>
     <emphasis>{+prevent-setting-cookies}</emphasis>
     <emphasis>.example.com</emphasis>
    </literallayout>
  </listitem>
 </varlistentry>

 <varlistentry>
  <term>Notes:</term>
  <listitem>
   <para>
    Often used in conjunction with <quote>+prevent-reading-cookies</quote> to 
    disable cookies completely (see above).
   </para>
  </listitem>
 </varlistentry>

</variablelist>
</sect4>


<!--   ~~~~~       Nvarlistentryew section      ~~~~~     -->
<sect4 id="kill-popup">
<title><emphasis>+kill-popups<anchor id="kill-popups"></emphasis></title>
<variablelist>
 <varlistentry>
  <term>Type:</term>
  <!-- Boolean, Parameterized, Multi-value -->
  <listitem>
   <para>Boolean.</para>
  </listitem>
 </varlistentry>

 <varlistentry>
  <term>Typical uses:</term>
  <listitem>
   <para>
    Stop those annoying JavaScript pop-up windows! 
   </para>
  </listitem>
 </varlistentry>

 <varlistentry>
  <term>Possible values:</term>
  <listitem>
   <para>
    N/A
   </para>
  </listitem>
 </varlistentry>
 
 <varlistentry>
  <term>Example usage:</term>
  <listitem>
    <literallayout>
     <emphasis>{+kill-popups}</emphasis>
     <emphasis>.example.com</emphasis>
    </literallayout>
  </listitem>
 </varlistentry>

 <varlistentry>
  <term>Notes:</term>
  <listitem>
   <para>
    <quote>+kill-popups</quote> uses a built in filter to disable pop-ups
    that use the <literal>window.open()</literal> function, etc. This is 
    one of the first actions processed by <application>Privoxy</application>
    as it contacts the remote web server. This action is not always 100% reliable, 
    and is supplemented by <quote>+filter{<emphasis>popups</emphasis>}</quote>.
    </para>
  <!-- 
   <para>
    An alternate spelling is <quote>+kill-popup</quote>, which is 
    interchangeable.
   </para>
 --> 
  </listitem>
 </varlistentry>

</variablelist>
</sect4>


<!--   ~~~~~       New section      ~~~~~     -->
<sect4 id="send-vanilla-wafer">
<title><emphasis>+send-vanilla-wafer</emphasis></title>

<variablelist>
 <varlistentry>
  <term>Type:</term>
  <!-- Boolean, Parameterized, Multi-value -->
  <listitem>
   <para>Boolean.</para>
  </listitem>
 </varlistentry>

 <varlistentry>
  <term>Typical uses:</term>
  <listitem>
   <para>
    Sends a cookie for every site stating that you do not accept any copyright
    on cookies sent to you, and asking them not to track you.
   </para>
  </listitem>
 </varlistentry>

 <varlistentry>
  <term>Possible values:</term>
  <listitem>
   <para>
    N/A
   </para>
  </listitem>
 </varlistentry>
 
 <varlistentry>
  <term>Example usage:</term>
  <listitem>
    <literallayout>
     <emphasis>{+send-vanilla-wafer}</emphasis>
     <emphasis>.example.com</emphasis>
    </literallayout>
  </listitem>
 </varlistentry>

 <varlistentry>
  <term>Notes:</term>
  <listitem>
   <para>
    This action only applies if you are using a <filename>jarfile</filename>
    for saving cookies. Of course, this is a (relatively) unique header and 
    could conceivably be used to track you.
   </para>
  </listitem>
 </varlistentry>

</variablelist>
</sect4>


<!--   ~~~~~       New section      ~~~~~     -->
<sect4 id="send-wafer">
<title><emphasis>+send-wafer</emphasis></title>

<variablelist>
 <varlistentry>
  <term>Type:</term>
  <!-- Boolean, Parameterized, Multi-value -->
  <listitem>
   <para>Multi-value.</para>
  </listitem>
 </varlistentry>

 <varlistentry>
  <term>Typical uses:</term>
  <listitem>
   <para>
    This allows you to send an arbitrary, user definable cookie.
   </para>
  </listitem>
 </varlistentry>

 <varlistentry>
  <term>Possible values:</term>
  <listitem>
   <para>
    User specified cookie name and corresponding value.
   </para>
  </listitem>
 </varlistentry>
 
 <varlistentry>
  <term>Example usage:</term>
  <listitem>
    <literallayout>
     <emphasis>{+send-wafer{name=value}}</emphasis>
     <emphasis>.example.com</emphasis>
    </literallayout>
  </listitem>
 </varlistentry>

 <varlistentry>
  <term>Notes:</term>
  <listitem>
   <para>
    This can be specified multiple times in order to add as many cookies as you
    like.
   </para>
  </listitem>
 </varlistentry>

</variablelist>
</sect4>


<!--   ~~~~~       New section      ~~~~~     -->
<sect4 id="act-examples" renderas="sect3">
<title>Actions Examples</title>
<para>
 Note that the meaning of any of the above examples is reversed by preceding
 the action with a <quote>-</quote>, in place of the <quote>+</quote>. Also, 
 that some actions are turned on in the default section of the actions file, 
 and require little to no additional configuration. These are just <quote>on</quote>.
 But, other actions that are turned on the default section <emphasis>do
 typically require</emphasis> exceptions to be listed in the lower sections of
 actions file. E.g. by default no URLs are <quote>blocked</quote> (i.e. in 
 the default definitions of <filename>default.action</filename>). We need 
 exceptions to this in order to enable ad blocking.
</para>

<para>
 Some examples:
</para>

<para>
 Turn off cookies by default, then allow a few through for specified sites 
 (showing an excerpt from the <quote>default</quote> section of an actions
 file ONLY):
</para>
  
<para>
 <literal>
  <msgtext> 
   <literallayout>
 # Excerpt only:
 # Allow cookies to and from the server, but
 # for this browser session ONLY
 { 
   # other actions normally listed here...
   -prevent-setting-cookies \
   -prevent-reading-cookies \
   +session-cookies-only   \  
 }
 / # match all URLs

 # Exceptions to the above, sites that benefit from persistent cookies
 # that are saved from one browser session to the next.
 { -session-cookies-only }
  .javasoft.com
  .sun.com
  .yahoo.com
  .msdn.microsoft.com
  .redhat.com

   </literallayout>
  </msgtext> 
 </literal>
</para>

<para>
 Now turn off <quote>fast redirects</quote>, and then we allow two exceptions:
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
 # Turn them off (excerpt only)!
 {
  # other actions normally listed here...
  +fast-redirects
 }
 / # match all URLs
 
 # Reverse it for these two sites, which don't work right without it.
 {-fast-redirects}
  www.ukc.ac.uk/cgi-bin/wac\.cgi\?
  login.yahoo.com
   </literallayout>
  </msgtext> 
 </literal>
</para>

<para>
 Turn on page filtering according to rules in the defined sections 
 of <filename>default.filter</filename>, and make one exception for 
 Sourceforge:
 </para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
 # Run everything through the filter file, using only certain
 # specified sections:
 {
  # other actions normally listed here...
  +filter{html-annoyances} +filter{js-annoyances} +filter{kill-popups}\
  +filter{webbugs} +filter{nimda} +filter{banners-by-size}
 }
 / #match all URLs
              
 # Then disable filtering of code from all sourceforge domains!
 {-filter}
  .sourceforge.net
   </literallayout>
  </msgtext> 
 </literal>
</para>

<para>
 Now some URLs that we want <quote>blocked</quote> (normally generates 
 the <quote>blocked</quote> banner). Typically, the <quote>block</quote>
 action is off by default in the upper section of an actions file, then enabled
 against certain URLs and patterns in the lower part of the file. Many of these use <link
 linkend="regex">regular expressions</link> that will expand to match multiple
 URLs: </para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
  # Blocklist:
  {+block}
  ad*.
  .*ads.
  banner?.
  count*.
  /.*count(er)?\.(pl|cgi|exe|dll|asp|php[34]?)
  /(?:.*/)?(publicite|werbung|rekla(ma|me|am)|annonse|maino(kset|nta|s)?)/
  .hitbox.com 
  /.*/(ng)?adclient\.cgi
  /.*/(plain|live|rotate)[-_.]?ads?/
  /.*/abanners/
  /autoads/
   </literallayout>
  </msgtext> 
 </literal>
</para>

<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>
</sect4>

</sect3>

<!--  ~  End section  ~  -->


<!--   ~~~~~       New section      ~~~~~     -->
<sect3 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 <quote>actions</quote>.
 These can in turn be invoked just like the built-in <quote>actions</quote>.
 Currently, an alias can contain any character except space, tab, <quote>=</quote>,
 <quote>{</quote> or <quote>}</quote>. But please use only <quote>a</quote>-
 <quote>z</quote>, <quote>0</quote>-<quote>9</quote>, <quote>+</quote>, and
 <quote>-</quote>. Alias names are not case sensitive, and 
 <emphasis>must be defined before other actions</emphasis> in the
 actions file! And there can only be one set of <quote>aliases</quote>
 defined per file. Each actions file may have its own aliases, but they are 
 only visible within that file.
</para>

<para>
 Now let's define a few aliases:
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
 # Useful custom aliases we can use later. These must come first!
 {{alias}}
 +prevent-cookies = +prevent-setting-cookies +prevent-reading-cookies
 -prevent-cookies = -prevent-setting-cookies -prevent-reading-cookies
 fragile     = -block -prevent-cookies -filter -fast-redirects -hide-referer -kill-popups
 shop        = -prevent-cookies -filter -fast-redirects
 +imageblock = +block +handle-as-image

 # Aliases defined from other aliases, for people who don't like to type 
 # too much:  ;-)
 c0 = +prevent-cookies
 c1 = -prevent-cookies
 #... etc.  Customize to your heart's content.
   </literallayout>
  </msgtext> 
 </literal>
</para>

<para>
 Some examples using our <quote>shop</quote> and <quote>fragile</quote>
 aliases from above. These would appear in the lower sections of an 
 actions file as exceptions to the default actions (as defined in the 
 upper section):
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
 # These sites are very complex and require
 # minimal interference.
 {fragile}
  .office.microsoft.com
  .windowsupdate.microsoft.com
  .nytimes.com

 # Shopping sites - but we still want to block ads.
 {shop}
  .quietpc.com
  .worldpay.com   # for quietpc.com
  .scan.co.uk

 # These shops require pop-ups also 
 {shop -kill-popups}
  .dabs.com
  .overclockers.co.uk
   </literallayout>
  </msgtext> 
 </literal>
</para>

<para>
 The <quote>shop</quote> and <quote>fragile</quote> aliases are often used for 
 <quote>problem</quote> sites that require most actions to be disabled 
 in order to function properly.

</para>

</sect3>
</sect2>

<!--  ~  End section  ~  -->


<!--   ~~~~~       New section      ~~~~~     -->
<sect2 id="filter-file">
<title>The Filter File</title>
<para>
 Any web page can be dynamically modified with the filter file. This
 modification can be removal, or re-writing, of any web page content,
 including tags and non-visible content. The default filter file is
 <filename>default.filter</filename>, located in the config directory. 
</para>

<para>
 This is potentially a very powerful feature, and requires knowledge of both 
 <quote>regular expression</quote> and HTML in order create custom 
 filters. But, there are a number of useful filters included with 
 <application>Privoxy</application> for many common situations.
</para>

<para>
 The included example file is divided into sections. Each section begins 
 with the <literal>FILTER</literal> keyword, followed by the identifier 
 for that section, e.g. <quote>FILTER: webbugs</quote>. Each section performs
 a similar type of filtering, such as <quote>html-annoyances</quote>.
</para>

<para>
 This file uses regular expressions to alter or remove any string in the
 target page. The expressions can only operate on one line at a time. Some
 examples from the included default <filename>default.filter</filename>:
</para>

<para>
 Stop web pages from displaying annoying messages in the status bar by
 deleting such references:
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
 FILTER: html-annoyances

 # New browser windows should be resizeable and have a location and status
 # bar. Make it so.
 #
 s/resizable="?(no|0)"?/resizable=1/ig s/noresize/yesresize/ig
 s/location="?(no|0)"?/location=1/ig s/status="?(no|0)"?/status=1/ig
 s/scrolling="?(no|0|Auto)"?/scrolling=1/ig
 s/menubar="?(no|0)"?/menubar=1/ig 

 # The &lt;BLINK&gt; tag was a crime!
&n