+*<font color="red"><b>BINGO!</b></font> \
+*igx
+</pre>
+ </td>
+ </tr>
+ </table>
+
+ <p>The <tt class="LITERAL">x</tt> option in this job turns on extended
+ syntax, and allows for e.g. the liberal use of (non-interpreted!)
+ whitespace for nicer formatting.</p>
+
+ <p>You get the idea?</p>
+ </div>
+
+ <div class="SECT2">
+ <h2 class="SECT2"><a name="PREDEFINED-FILTERS" id=
+ "PREDEFINED-FILTERS">9.2. The Pre-defined Filters</a></h2>
+
+ <p>The distribution <tt class="FILENAME">default.filter</tt> file
+ contains a selection of pre-defined filters for your convenience:</p>
+
+ <div class="VARIABLELIST">
+ <dl>
+ <dt><span class="emphasis"><i class=
+ "EMPHASIS">js-annoyances</i></span></dt>
+
+ <dd>
+ <p>The purpose of this filter is to get rid of particularly
+ annoying JavaScript abuse. To that end, it</p>
+
+ <ul>
+ <li>
+ <p>replaces JavaScript references to the browser's referrer
+ information with the string "Not Your Business!". This
+ compliments the <tt class="LITERAL"><a href=
+ "actions-file.html#HIDE-REFERRER">hide-referrer</a></tt>
+ action on the content level.</p>
+ </li>
+
+ <li>
+ <p>removes the bindings to the DOM's <a href=
+ "http://www.w3.org/TR/2000/REC-DOM-Level-2-Events-20001113/events.html#Events-eventgroupings-htmlevents"
+ target="_top">unload event</a> which we feel has no right to
+ exist and is responsible for most <span class="QUOTE">"exit
+ consoles"</span>, i.e. nasty windows that pop up when you
+ close another one.</p>
+ </li>
+
+ <li>
+ <p>removes code that causes new windows to be opened with
+ undesired properties, such as being full-screen,
+ non-resizeable, without location, status or menu bar etc.</p>
+ </li>
+ </ul>
+
+ <p>Use with caution. This is an aggressive filter, and can break
+ sites that rely heavily on JavaScript.</p>
+ </dd>
+
+ <dt><span class="emphasis"><i class=
+ "EMPHASIS">js-events</i></span></dt>
+
+ <dd>
+ <p>This is a very radical measure. It removes virtually all
+ JavaScript event bindings, which means that scripts can not react
+ to user actions such as mouse movements or clicks, window
+ resizing etc, anymore. Use with caution!</p>
+
+ <p>We <span class="emphasis"><i class="EMPHASIS">strongly
+ discourage</i></span> using this filter as a default since it
+ breaks many legitimate scripts. It is meant for use only on
+ extra-nasty sites (should you really need to go there).</p>
+ </dd>
+
+ <dt><span class="emphasis"><i class=
+ "EMPHASIS">html-annoyances</i></span></dt>
+
+ <dd>
+ <p>This filter will undo many common instances of HTML based
+ abuse.</p>
+
+ <p>The <tt class="LITERAL">BLINK</tt> and <tt class=
+ "LITERAL">MARQUEE</tt> tags are neutralized (yeah baby!), and
+ browser windows will be created as resizeable (as of course they
+ should be!), and will have location, scroll and menu bars -- even
+ if specified otherwise.</p>
+ </dd>
+
+ <dt><span class="emphasis"><i class=
+ "EMPHASIS">content-cookies</i></span></dt>
+
+ <dd>
+ <p>Most cookies are set in the HTTP dialog, where they can be
+ intercepted by the <tt class="LITERAL"><a href=
+ "actions-file.html#CRUNCH-INCOMING-COOKIES">crunch-incoming-cookies</a></tt>
+ and <tt class="LITERAL"><a href=
+ "actions-file.html#CRUNCH-OUTGOING-COOKIES">crunch-outgoing-cookies</a></tt>
+ actions. But web sites increasingly make use of HTML meta tags
+ and JavaScript to sneak cookies to the browser on the content
+ level.</p>
+
+ <p>This filter disables most HTML and JavaScript code that reads
+ or sets cookies. It cannot detect all clever uses of these types
+ of code, so it should not be relied on as an absolute fix. Use it
+ wherever you would also use the cookie crunch actions.</p>
+ </dd>
+
+ <dt><span class="emphasis"><i class="EMPHASIS">refresh
+ tags</i></span></dt>
+
+ <dd>
+ <p>Disable any refresh tags if the interval is greater than nine
+ seconds (so that redirections done via refresh tags are not
+ destroyed). This is useful for dial-on-demand setups, or for
+ those who find this HTML feature annoying.</p>
+ </dd>
+
+ <dt><span class="emphasis"><i class=
+ "EMPHASIS">unsolicited-popups</i></span></dt>
+
+ <dd>
+ <p>This filter attempts to prevent only <span class=
+ "QUOTE">"unsolicited"</span> pop-up windows from opening, yet
+ still allow pop-up windows that the user has explicitly chosen to
+ open. It was added in version 3.0.1, as an improvement over
+ earlier such filters.</p>
+
+ <p>Technical note: The filter works by redefining the window.open
+ JavaScript function to a dummy function, <tt class=
+ "LITERAL">PrivoxyWindowOpen()</tt>, during the loading and
+ rendering phase of each HTML page access, and restoring the
+ function afterward.</p>
+
+ <p>This is recommended only for browsers that cannot perform this
+ function reliably themselves. And be aware that some sites
+ require such windows in order to function normally. Use with
+ caution.</p>
+ </dd>
+
+ <dt><span class="emphasis"><i class=
+ "EMPHASIS">all-popups</i></span></dt>
+
+ <dd>
+ <p>Attempt to prevent <span class="emphasis"><i class=
+ "EMPHASIS">all</i></span> pop-up windows from opening. Note this
+ should be used with even more discretion than the above, since it
+ is more likely to break some sites that require pop-ups for
+ normal usage. Use with caution.</p>
+ </dd>
+
+ <dt><span class="emphasis"><i class=
+ "EMPHASIS">img-reorder</i></span></dt>
+
+ <dd>
+ <p>This is a helper filter that has no value if used alone. It
+ makes the <tt class="LITERAL">banners-by-size</tt> and <tt class=
+ "LITERAL">banners-by-link</tt> (see below) filters more effective
+ and should be enabled together with them.</p>
+ </dd>
+
+ <dt><span class="emphasis"><i class=
+ "EMPHASIS">banners-by-size</i></span></dt>
+
+ <dd>
+ <p>This filter removes image tags purely based on what size they
+ are. Fortunately for us, many ads and banner images tend to
+ conform to certain standardized sizes, which makes this filter
+ quite effective for ad stripping purposes.</p>
+
+ <p>Occasionally this filter will cause false positives on images
+ that are not ads, but just happen to be of one of the standard
+ banner sizes.</p>
+
+ <p>Recommended only for those who require extreme ad blocking.
+ The default block rules should catch 95+% of all ads <span class=
+ "emphasis"><i class="EMPHASIS">without</i></span> this filter
+ enabled.</p>
+ </dd>
+
+ <dt><span class="emphasis"><i class=
+ "EMPHASIS">banners-by-link</i></span></dt>
+
+ <dd>
+ <p>This is an experimental filter that attempts to kill any
+ banners if their URLs seem to point to known or suspected click
+ trackers. It is currently not of much value and is not
+ recommended for use by default.</p>
+ </dd>
+
+ <dt><span class="emphasis"><i class=
+ "EMPHASIS">webbugs</i></span></dt>
+
+ <dd>
+ <p>Webbugs are small, invisible images (technically 1X1 GIF
+ images), that are used to track users across websites, and
+ collect information on them. As an HTML page is loaded by the
+ browser, an embedded image tag causes the browser to contact a
+ third-party site, disclosing the tracking information through the
+ requested URL and/or cookies for that third-party domain, without
+ the user ever becoming aware of the interaction with the
+ third-party site. HTML-ized spam also uses a similar technique to
+ verify email addresses.</p>
+
+ <p>This filter removes the HTML code that loads such <span class=
+ "QUOTE">"webbugs"</span>.</p>
+ </dd>
+
+ <dt><span class="emphasis"><i class=
+ "EMPHASIS">tiny-textforms</i></span></dt>
+
+ <dd>
+ <p>A rather special-purpose filter that can be used to enlarge
+ textareas (those multi-line text boxes in web forms) and turn off
+ hard word wrap in them. It was written for the sourceforge.net
+ tracker system where such boxes are a nuisance, but it can be
+ handy on other sites, too.</p>
+
+ <p>It is not recommended to use this filter as a default.</p>
+ </dd>
+
+ <dt><span class="emphasis"><i class=
+ "EMPHASIS">jumping-windows</i></span></dt>
+
+ <dd>
+ <p>Many consider windows that move, or resize themselves to be
+ abusive. This filter neutralizes the related JavaScript code.
+ Note that some sites might not display or behave as intended when
+ using this filter. Use with caution.</p>
+ </dd>
+
+ <dt><span class="emphasis"><i class=
+ "EMPHASIS">frameset-borders</i></span></dt>
+
+ <dd>
+ <p>Some web designers seem to assume that everyone in the world
+ will view their web sites using the same browser brand and
+ version, screen resolution etc, because only that assumption
+ could explain why they'd use static frame sizes, yet prevent
+ their frames from being resized by the user, should they be too
+ small to show their whole content.</p>
+
+ <p>This filter removes the related HTML code. It should only be
+ applied to sites which need it.</p>
+ </dd>
+
+ <dt><span class="emphasis"><i class=
+ "EMPHASIS">demoronizer</i></span></dt>
+
+ <dd>
+ <p>Many Microsoft products that generate HTML use non-standard
+ extensions (read: violations) of the ISO 8859-1 aka Latin-1
+ character set. This can cause those HTML documents to display
+ with errors on standard-compliant platforms.</p>
+
+ <p>This filter translates the MS-only characters into Latin-1
+ equivalents. It is not necessary when using MS products, and will
+ cause corruption of all documents that use 8-bit character sets
+ other than Latin-1. It's mostly worthwhile for Europeans on
+ non-MS platforms, if weird garbage characters sometimes appear on
+ some pages, or user agents that don't correct for this on the
+ fly.</p>
+ </dd>
+
+ <dt><span class="emphasis"><i class=
+ "EMPHASIS">shockwave-flash</i></span></dt>
+
+ <dd>
+ <p>A filter for shockwave haters. As the name suggests, this
+ filter strips code out of web pages that is used to embed
+ shockwave flash objects.</p>
+ </dd>
+
+ <dt><span class="emphasis"><i class=
+ "EMPHASIS">quicktime-kioskmode</i></span></dt>
+
+ <dd>
+ <p>Change HTML code that embeds Quicktime objects so that
+ kioskmode, which prevents saving, is disabled.</p>
+ </dd>
+
+ <dt><span class="emphasis"><i class="EMPHASIS">fun</i></span></dt>
+
+ <dd>
+ <p>Text replacements for subversive browsing fun. Make fun of
+ your favorite Monopolist or play buzzword bingo.</p>
+ </dd>
+
+ <dt><span class="emphasis"><i class=
+ "EMPHASIS">crude-parental</i></span></dt>
+
+ <dd>
+ <p>A demonstration-only filter that shows how <span class=
+ "APPLICATION">Privoxy</span> can be used to delete web content on
+ a keyword basis.</p>
+ </dd>
+
+ <dt><span class="emphasis"><i class=
+ "EMPHASIS">ie-exploits</i></span></dt>
+
+ <dd>
+ <p>An experimental collection of text replacements to disable
+ malicious HTML and JavaScript code that exploits known security
+ holes in Internet Explorer.</p>
+
+ <p>Presently, it only protects against Nimda and a cross-site
+ scripting bug, and would need active maintenance to provide more
+ substantial protection.</p>
+ </dd>
+
+ <dt><span class="emphasis"><i class=
+ "EMPHASIS">site-specifics</i></span></dt>
+
+ <dd>
+ <p>Some web sites have very specific problems, the cure for which
+ doesn't apply anywhere else, or could even cause damage on other
+ sites.</p>
+
+ <p>This is a collection of such site-specific cures which should
+ only be applied to the sites they were intended for, which is
+ what the supplied <tt class="FILENAME">default.action</tt> file
+ does. Users shouldn't need to change anything regarding this
+ filter.</p>
+ </dd>
+
+ <dt><span class="emphasis"><i class=
+ "EMPHASIS">google</i></span></dt>
+
+ <dd>
+ <p>A CSS based block for Google text ads. Also removes a width
+ limitation and the toolbar advertisement.</p>
+ </dd>
+
+ <dt><span class="emphasis"><i class=
+ "EMPHASIS">yahoo</i></span></dt>
+
+ <dd>
+ <p>Another CSS based block, this time for Yahoo text ads. And
+ removes a width limitation as well.</p>
+ </dd>
+
+ <dt><span class="emphasis"><i class="EMPHASIS">msn</i></span></dt>
+
+ <dd>
+ <p>Another CSS based block, this time for MSN text ads. And
+ removes tracking URLs, as well as a width limitation.</p>
+ </dd>
+
+ <dt><span class="emphasis"><i class=
+ "EMPHASIS">blogspot</i></span></dt>
+
+ <dd>
+ <p>Cleans up some Blogspot blogs. Read the fine print before
+ using this one!</p>
+
+ <p>This filter also intentionally removes some navigation stuff
+ and sets the page width to 100%. As a result, some rounded
+ <span class="QUOTE">"corners"</span> would appear to early or not
+ at all and as fixing this would require a browser that
+ understands background-size (CSS3), they are removed instead.</p>
+ </dd>
+
+ <dt><span class="emphasis"><i class=
+ "EMPHASIS">xml-to-html</i></span></dt>
+
+ <dd>
+ <p>Server-header filter to change the Content-Type from xml to
+ html.</p>
+ </dd>
+
+ <dt><span class="emphasis"><i class=
+ "EMPHASIS">html-to-xml</i></span></dt>
+
+ <dd>
+ <p>Server-header filter to change the Content-Type from html to
+ xml.</p>
+ </dd>
+
+ <dt><span class="emphasis"><i class=
+ "EMPHASIS">no-ping</i></span></dt>
+
+ <dd>
+ <p>Removes the non-standard <tt class="LITERAL">ping</tt>
+ attribute from anchor and area HTML tags.</p>
+ </dd>
+
+ <dt><span class="emphasis"><i class=
+ "EMPHASIS">hide-tor-exit-notation</i></span></dt>
+
+ <dd>
+ <p>Client-header filter to remove the <b class="COMMAND">Tor</b>
+ exit node notation found in Host and Referer headers.</p>
+
+ <p>If <span class="APPLICATION">Privoxy</span> and <b class=
+ "COMMAND">Tor</b> are chained and <span class=
+ "APPLICATION">Privoxy</span> is configured to use socks4a, one
+ can use <span class=
+ "QUOTE">"http://www.example.org.foobar.exit/"</span> to access
+ the host <span class="QUOTE">"www.example.org"</span> through the
+ <b class="COMMAND">Tor</b> exit node <span class=
+ "QUOTE">"foobar"</span>.</p>
+
+ <p>As the HTTP client isn't aware of this notation, it treats the
+ whole string <span class=
+ "QUOTE">"www.example.org.foobar.exit"</span> as host and uses it
+ for the <span class="QUOTE">"Host"</span> and <span class=
+ "QUOTE">"Referer"</span> headers. From the server's point of view
+ the resulting headers are invalid and can cause problems.</p>
+
+ <p>An invalid <span class="QUOTE">"Referer"</span> header can
+ trigger <span class="QUOTE">"hot-linking"</span> protections, an
+ invalid <span class="QUOTE">"Host"</span> header will make it
+ impossible for the server to find the right vhost (several
+ domains hosted on the same IP address).</p>
+
+ <p>This client-header filter removes the <span class=
+ "QUOTE">"foo.exit"</span> part in those headers to prevent the
+ mentioned problems. Note that it only modifies the HTTP headers,
+ it doesn't make it impossible for the server to detect your
+ <b class="COMMAND">Tor</b> exit node based on the IP address the
+ request is coming from.</p>
+ </dd>
+ </dl>
+ </div>
+ </div>
+ </div>
+
+ <div class="NAVFOOTER">
+ <hr align="left" width="100%">
+
+ <table summary="Footer navigation table" width="100%" border="0"
+ cellpadding="0" cellspacing="0">
+ <tr>
+ <td width="33%" align="left" valign="top"><a href="actions-file.html"
+ accesskey="P">Prev</a></td>
+
+ <td width="34%" align="center" valign="top"><a href="index.html"
+ accesskey="H">Home</a></td>
+
+ <td width="33%" align="right" valign="top"><a href="templates.html"
+ accesskey="N">Next</a></td>
+ </tr>
+
+ <tr>
+ <td width="33%" align="left" valign="top">Actions Files</td>
+
+ <td width="34%" align="center" valign="top"> </td>
+
+ <td width="33%" align="right" valign="top">Privoxy's Template
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