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39 >Privoxy 3.0.4 User Manual</TH
81 >14.1. Regular Expressions</H2
86 > uses Perl-style <SPAN
91 HREF="actions-file.html"
95 HREF="filter-file.html"
99 HREF="http://www.pcre.org/"
108 > If you are reading this, you probably don't understand what <SPAN
112 > are, or what they can do. So this will be a very brief
113 introduction only. A full explanation would require a <A
114 HREF="http://www.oreilly.com/catalog/regex/"
119 > Regular expressions provide a language to describe patterns that can be
120 run against strings of characters (letter, numbers, etc), to see if they
121 match the string or not. The patterns are themselves (sometimes complex)
122 strings of literal characters, combined with wild-cards, and other special
123 characters, called meta-characters. The <SPAN
125 >"meta-characters"</SPAN
127 special meanings and are used to build complex patterns to be matched against.
128 Perl Compatible Regular Expressions are an especially convenient
132 > of the regular expression language.</P
134 > To make a simple analogy, we do something similar when we use wild-card
135 characters when listing files with the <B
142 > matches all filenames. The <SPAN
146 character here is the asterisk which matches any and all characters. We can be
147 more specific and use <TT
150 > to match just individual
153 >"dir file?.text"</SPAN
161 >, etc. We are pattern
162 matching, using a similar technique to <SPAN
164 >"regular expressions"</SPAN
167 > Regular expressions do essentially the same thing, but are much, much more
168 powerful. There are many more <SPAN
170 >"special characters"</SPAN
172 building complex patterns however. Let's look at a few of the common ones,
173 and then some examples:</P
188 > - Matches any single character, e.g. <SPAN
226 > - The preceding character or expression is matched ZERO or ONE
249 > - The preceding character or expression is matched ONE or MORE
272 > - The preceding character or expression is matched ZERO or MORE
298 > character denotes that
299 the following character should be taken literally. This is used where one of the
300 special characters (e.g. <SPAN
303 >) needs to be taken literally and
304 not as a special meta-character. Example: <SPAN
306 >"example\.com"</SPAN
308 sure the period is recognized only as a period (and not expanded to its
309 meta-character meaning of any single character).
331 > - Characters enclosed in brackets will be matched if
332 any of the enclosed characters are encountered. For instance, <SPAN
336 matches any numeric digit (zero through nine). As an example, we can combine
340 > to match any digit one of more times: <SPAN
365 > - parentheses are used to group a sub-expression,
366 or multiple sub-expressions.
391 > character works like an
395 > conditional statement. A match is successful if the
396 sub-expression on either side of <SPAN
399 > matches. As an example:
402 >"/(this|that) example/"</SPAN
403 > uses grouping and the bar character
404 and would match either <SPAN
406 >"this example"</SPAN
420 > These are just some of the ones you are likely to use when matching URLs with
424 >, and is a long way from a definitive
425 list. This is enough to get us started with a few simple examples which may
426 be more illuminating:</P
438 that uses the common combination of <SPAN
445 denote any character, zero or more times. In other words, any string at all.
446 So we start with a literal forward slash, then our regular expression pattern
450 >) another literal forward slash, the string
454 >, another forward slash, and lastly another
459 a directory path here. This will match any file with the path that has a
460 directory named <SPAN
467 any characters, and this could conceivably be more forward slashes, so it
468 might expand into a much longer looking path. For example, this could match:
471 >"/eye/hate/spammers/banners/annoy_me_please.gif"</SPAN
475 >"/banners/annoying.html"</SPAN
476 >, or almost an infinite number of other
477 possible combinations, just so it has <SPAN
483 > And now something a little more complex:</P
491 >/.*/adv((er)?ts?|ertis(ing|ements?))?/</TT
495 We have several literal forward slashes again (<SPAN
499 building another expression that is a file path statement. We have another
503 >, so we are matching against any conceivable sub-path, just so
504 it matches our expression. The only true literal that <SPAN
511 > our pattern is <SPAN
515 the forward slashes. What comes after the <SPAN
519 interesting part. </P
524 > means the preceding expression (either a
525 literal character or anything grouped with <SPAN
529 can exist or not, since this means either zero or one match. So
532 >"((er)?ts?|ertis(ing|ements?))"</SPAN
533 > is optional, as are the
534 individual sub-expressions: <SPAN
540 >"(ing|ements?)"</SPAN
551 >. We have two of those. For instance,
554 >"(ing|ements?)"</SPAN
555 >, can expand to match either <SPAN
568 >. What is being done here, is an
569 attempt at matching as many variations of <SPAN
571 >"advertisement"</SPAN
573 similar, as possible. So this would expand to match just <SPAN
589 >"advertisement"</SPAN
593 >"advertisements"</SPAN
594 >. You get the idea. But it would not match
597 >"advertizements"</SPAN
601 >). We could fix that by
602 changing our regular expression to:
605 >"/.*/adv((er)?ts?|erti(s|z)(ing|ements?))?/"</SPAN
606 >, which would then match
615 >/.*/advert[0-9]+\.(gif|jpe?g)</TT
619 another path statement with forward slashes. Anything in the square brackets
623 > can be matched. This is using <SPAN
627 shorthand expression to mean any digit one through nine. It is the same as
631 >. So any digit matches. The <SPAN
635 means one or more of the preceding expression must be included. The preceding
636 expression here is what is in the square brackets -- in this case, any digit
637 one through nine. Then, at the end, we have a grouping: <SPAN
641 This includes a <SPAN
644 >, so this needs to match the expression on
645 either side of that bar character also. A simple <SPAN
648 > on one side, and the other
649 side will in turn match either <SPAN
659 > means the letter <SPAN
663 can be matched once or not at all. So we are building an expression here to
664 match image GIF or JPEG type image file. It must include the literal
668 >, then one or more digits, and a <SPAN
672 (which is now a literal, and not a special character, since it is escaped
676 >), and lastly either <SPAN
686 >. Some possible matches would
689 >"//advert1.jpg"</SPAN
693 >"/nasty/ads/advert1234.gif"</SPAN
697 >"/banners/from/hell/advert99.jpg"</SPAN
698 >. It would not match
702 > (no leading slash), or
705 >"/adverts232.jpg"</SPAN
706 > (the expression does not include an
712 >"/advert1.jsp"</SPAN
717 in the expression anywhere).</P
719 > We are barely scratching the surface of regular expressions here so that you
720 can understand the default <SPAN
724 configuration files, and maybe use this knowledge to customize your own
725 installation. There is much, much more that can be done with regular
726 expressions. Now that you know enough to get started, you can learn more on
729 > More reading on Perl Compatible Regular expressions:
731 HREF="http://perldoc.perl.org/perlre.html"
733 >http://perldoc.perl.org/perlre.html</A
736 > For information on regular expression based substitutions and their applications
737 in filters, please see the <A
738 HREF="filter-file.html"
739 >filter file tutorial</A
753 >'s Internal Pages</H2
758 > proxies each requested
759 web page, it is easy for <SPAN
763 trap certain special URLs. In this way, we can talk directly to
768 configured, see how our rules are being applied, change these
769 rules and other configuration options, and even turn
773 > filtering off, all with
774 a web browser. </P
776 > The URLs listed below are the special ones that allow direct access
784 > must be running to access these. If
785 not, you will get a friendly error message. Internet access is not
804 HREF="http://config.privoxy.org/"
806 >http://config.privoxy.org/</A
811 > There is a shortcut: <A
816 doesn't provide a fall-back to a real page, in case the request is not
826 Show information about the current configuration, including viewing and
827 editing of actions files:
837 HREF="http://config.privoxy.org/show-status"
839 >http://config.privoxy.org/show-status</A
847 Show the source code version numbers:
857 HREF="http://config.privoxy.org/show-version"
859 >http://config.privoxy.org/show-version</A
867 Show the browser's request headers:
877 HREF="http://config.privoxy.org/show-request"
879 >http://config.privoxy.org/show-request</A
887 Show which actions apply to a URL and why:
897 HREF="http://config.privoxy.org/show-url-info"
899 >http://config.privoxy.org/show-url-info</A
907 Toggle Privoxy on or off. In this case, <SPAN
911 to run, but only as a pass-through proxy, with no actions taking place:
921 HREF="http://config.privoxy.org/toggle"
923 >http://config.privoxy.org/toggle</A
928 > Short cuts. Turn off, then on:
938 HREF="http://config.privoxy.org/toggle?set=disable"
940 >http://config.privoxy.org/toggle?set=disable</A
952 HREF="http://config.privoxy.org/toggle?set=enable"
954 >http://config.privoxy.org/toggle?set=enable</A
962 > These may be bookmarked for quick reference. See next. </P
970 >14.2.1. Bookmarklets</H3
972 > Below are some <SPAN
974 >"bookmarklets"</SPAN
975 > to allow you to easily access a
979 > version of some of <SPAN
983 special pages. They are designed for MS Internet Explorer, but should work
984 equally well in Netscape, Mozilla, and other browsers which support
985 JavaScript. They are designed to run directly from your bookmarks - not by
986 clicking the links below (although that should work for testing).</P
988 > To save them, right-click the link and choose <SPAN
990 >"Add to Favorites"</SPAN
994 >"Add Bookmark"</SPAN
995 > (Netscape). You will get a warning that
998 >"may not be safe"</SPAN
999 > - just click OK. Then you can run the
1000 Bookmarklet directly from your favorites/bookmarks. For even faster access,
1001 you can put them on the <SPAN
1004 > bar (IE) or the <SPAN
1008 > (Netscape), and run them with a single click. </P
1016 HREF="javascript:void(window.open('http://config.privoxy.org/toggle?mini=y&set=enabled','ijbstatus','width=250,height=100,resizable=yes,scrollbars=no,toolbar=no,location=no,directories=no,status=no,menubar=no,copyhistory=no').focus());"
1018 >Privoxy - Enable</A
1025 HREF="javascript:void(window.open('http://config.privoxy.org/toggle?mini=y&set=disabled','ijbstatus','width=250,height=100,resizable=yes,scrollbars=no,toolbar=no,location=no,directories=no,status=no,menubar=no,copyhistory=no').focus());"
1027 >Privoxy - Disable</A
1034 HREF="javascript:void(window.open('http://config.privoxy.org/toggle?mini=y&set=toggle','ijbstatus','width=250,height=100,resizable=yes,scrollbars=no,toolbar=no,location=no,directories=no,status=no,menubar=no,copyhistory=no').focus());"
1036 >Privoxy - Toggle Privoxy</A
1037 > (Toggles between enabled and disabled)
1043 HREF="javascript:void(window.open('http://config.privoxy.org/toggle?mini=y','ijbstatus','width=250,height=2,resizable=yes,scrollbars=no,toolbar=no,location=no,directories=no,status=no,menubar=no,copyhistory=no').focus());"
1045 >Privoxy- View Status</A
1052 HREF="javascript:void(window.open('http://config.privoxy.org/show-url-info?url='+escape(location.href),'Why').focus());"
1061 > Credit: The site which gave us the general idea for these bookmarklets is
1063 HREF="http://www.bookmarklets.com/"
1065 >www.bookmarklets.com</A
1067 have more information about bookmarklets. </P
1077 >14.3. Chain of Events</H2
1079 > Let's take a quick look at the basic sequence of events when a web page is
1080 requested by your browser and <SPAN
1090 > First, your web browser requests a web page. The browser knows to send
1091 the request to <SPAN
1094 >, which will in turn,
1095 relay the request to the remote web server after passing the following
1104 > traps any request for its own internal CGI
1109 >) and sends the CGI page back to the browser.
1117 > checks to see if the URL
1119 HREF="actions-file.html#BLOCK"
1125 so, the URL is then blocked, and the remote web server will not be contacted.
1127 HREF="actions-file.html#HANDLE-AS-IMAGE"
1130 >"+handle-as-image"</SPAN
1133 is then checked and if it does not match, an
1137 > page is sent back. Otherwise, if it does match,
1138 an image is returned. The type of image depends on the setting of <A
1139 HREF="actions-file.html#SET-IMAGE-BLOCKER"
1142 >"+set-image-blocker"</SPAN
1145 (blank, checkerboard pattern, or an HTTP redirect to an image elsewhere).
1150 > Untrusted URLs are blocked. If URLs are being added to the
1154 > file, then that is done.
1159 > If the URL pattern matches the <A
1160 HREF="actions-file.html#FAST-REDIRECTS"
1163 >"+fast-redirects"</SPAN
1166 it is then processed. Unwanted parts of the requested URL are stripped.
1171 > Now the rest of the client browser's request headers are processed. If any
1172 of these match any of the relevant actions (e.g. <A
1173 HREF="actions-file.html#HIDE-USER-AGENT"
1176 >"+hide-user-agent"</SPAN
1179 etc.), headers are suppressed or forged as determined by these actions and
1185 > Now the web server starts sending its response back (i.e. typically a web page and related
1191 > First, the server headers are read and processed to determine, among other
1192 things, the MIME type (document type) and encoding. The headers are then
1193 filtered as determined by the
1195 HREF="actions-file.html#CRUNCH-INCOMING-COOKIES"
1198 >"+crunch-incoming-cookies"</SPAN
1202 HREF="actions-file.html#SESSION-COOKIES-ONLY"
1205 >"+session-cookies-only"</SPAN
1209 HREF="actions-file.html#DOWNGRADE-HTTP-VERSION"
1212 >"+downgrade-http-version"</SPAN
1221 HREF="actions-file.html#KILL-POPUPS"
1224 >"+kill-popups"</SPAN
1227 action applies, and it is an HTML or JavaScript document, the popup-code in the
1228 response is filtered on-the-fly as it is received.
1234 HREF="actions-file.html#FILTER"
1241 HREF="actions-file.html#DEANIMATE-GIFS"
1244 >"+deanimate-gifs"</SPAN
1247 action applies (and the document type fits the action), the rest of the page is
1248 read into memory (up to a configurable limit). Then the filter rules (from
1252 > and any other filter files) are
1253 processed against the buffered content. Filters are applied in the order
1254 they are specified in one of the filter files. Animated GIFs, if present,
1255 are reduced to either the first or last frame, depending on the action
1256 setting.The entire page, which is now filtered, is then sent by
1260 > back to your browser.
1264 HREF="actions-file.html#FILTER"
1271 HREF="actions-file.html#DEANIMATE-GIFS"
1274 >"+deanimate-gifs"</SPAN
1280 > passes the raw data through
1281 to the client browser as it becomes available.
1286 > As the browser receives the now (possibly filtered) page content, it
1287 reads and then requests any URLs that may be embedded within the page
1288 source, e.g. ad images, stylesheets, JavaScript, other HTML documents (e.g.
1289 frames), sounds, etc. For each of these objects, the browser issues a new
1290 request. And each such request is in turn processed as above. Note that a
1291 complex web page may have many such embedded URLs.
1304 >14.4. Anatomy of an Action</H2
1311 HREF="actions-file.html#ACTIONS"
1314 HREF="actions-file.html#FILTER"
1317 to any given URL can be complex, and not always so
1318 easy to understand what is happening. And sometimes we need to be able to
1329 doing. Especially, if something <SPAN
1333 is causing us a problem inadvertently. It can be a little daunting to look at
1334 the actions and filters files themselves, since they tend to be filled with
1336 HREF="appendix.html#REGEX"
1337 >regular expressions</A
1338 > whose consequences are not
1339 always so obvious. </P
1341 > One quick test to see if <SPAN
1344 > is causing a problem
1345 or not, is to disable it temporarily. This should be the first troubleshooting
1347 HREF="appendix.html#BOOKMARKLETS"
1348 >the Bookmarklets</A
1349 > section on a quick
1350 and easy way to do this (be sure to flush caches afterward!). Looking at the
1351 logs is a good idea too.</P
1358 HREF="http://config.privoxy.org/show-url-info"
1360 >http://config.privoxy.org/show-url-info</A
1362 page that can show us very specifically how <SPAN
1366 are being applied to any given URL. This is a big help for troubleshooting.</P
1368 > First, enter one URL (or partial URL) at the prompt, and then
1373 how the current configuration will handle it. This will not
1374 help with filtering effects (i.e. the <A
1375 HREF="actions-file.html#FILTER"
1381 one of the filter files since this is handled very
1382 differently and not so easy to trap! It also will not tell you about any other
1383 URLs that may be embedded within the URL you are testing. For instance, images
1384 such as ads are expressed as URLs within the raw page source of HTML pages. So
1385 you will only get info for the actual URL that is pasted into the prompt area
1386 -- not any sub-URLs. If you want to know about embedded URLs like ads, you
1387 will have to dig those out of the HTML source. Use your browser's <SPAN
1391 > option for this. Or right click on the ad, and grab the
1394 > Let's try an example, <A
1395 HREF="http://google.com"
1399 and look at it one section at a time in a sample configuration (your real
1400 configuration may vary):</P
1410 > Matches for http://google.com:
1412 In file: default.action <SPAN
1422 -content-type-overwrite
1423 -crunch-client-header
1424 -crunch-if-none-match
1425 -crunch-incoming-cookies
1426 -crunch-outgoing-cookies
1427 -crunch-server-header
1428 +deanimate-gifs {last}
1429 -downgrade-http-version
1430 +fast-redirects {check-decoded-url}
1432 -filter {content-cookies}
1433 -filter {all-popups}
1434 -filter {banners-by-link}
1435 -filter {tiny-textforms}
1436 -filter {frameset-borders}
1437 -filter {demoronizer}
1438 -filter {shockwave-flash}
1439 -filter {quicktime-kioskmode}
1441 -filter {crude-parental}
1442 -filter {site-specifics}
1443 +filter {js-annoyances}
1444 +filter {html-annoyances}
1445 +filter {refresh-tags}
1446 +filter {unsolicited-popups}
1447 +filter {img-reorder}
1448 +filter {banners-by-size}
1450 +filter {jumping-windows}
1451 +filter {ie-exploits}
1452 -filter-client-headers
1453 -filter-server-headers
1455 -handle-as-empty-document
1457 -hide-accept-language
1458 -hide-content-disposition
1459 +hide-forwarded-for-headers
1460 +hide-from-header {block}
1461 -hide-if-modified-since
1462 +hide-referrer {forge}
1467 -overwrite-last-modified
1468 +prevent-compression
1472 +session-cookies-only
1473 +set-image-blocker {pattern}
1474 -treat-forbidden-connects-like-blocks }
1477 { -session-cookies-only }
1483 In file: user.action <SPAN
1490 (no matches in this file) </PRE
1496 > This is telling us how we have defined our
1498 HREF="actions-file.html#ACTIONS"
1504 which ones match for our test case, <SPAN
1508 Displayed is all the actions that are available to us. Remember,
1512 > sign denotes <SPAN
1522 >. So some are <SPAN
1529 >. Each example we try may provide a slightly different
1530 end result, depending on our configuration directives.</P
1533 is any matches for the <TT
1535 >standard.action</TT
1540 >. Then next is <SPAN
1547 > file. The large, multi-line listing,
1548 is how the actions are set to match for all URLs, i.e. our default settings.
1549 If you look at your <SPAN
1552 > file, this would be the section
1553 just below the <SPAN
1556 > section near the top. This will apply to
1557 all URLs as signified by the single forward slash at the end of the listing
1563 > But we can define additional actions that would be exceptions to these general
1564 rules, and then list specific URLs (or patterns) that these exceptions would
1565 apply to. Last match wins. Just below this then are two explicit matches for
1568 >".google.com"</SPAN
1569 >. The first is negating our previous cookie setting,
1571 HREF="actions-file.html#SESSION-COOKIES-ONLY"
1574 >"+session-cookies-only"</SPAN
1577 (i.e. not persistent). So we will allow persistent cookies for google, at
1578 least that is how it is in this example. The second turns
1587 HREF="actions-file.html#FAST-REDIRECTS"
1590 >"+fast-redirects"</SPAN
1593 action, allowing this to take place unmolested. Note that there is a leading
1596 >".google.com"</SPAN
1597 >. This will match any hosts and
1598 sub-domains, in the google.com domain also, such as
1601 >"www.google.com"</SPAN
1602 >. So, apparently, we have these two actions
1603 defined somewhere in the lower part of our <TT
1610 > is referenced somewhere in these latter
1616 > file, we again have no hits.
1617 So there is nothing google-specific that we might have added to our own, local
1620 > And finally we pull it all together in the bottom section and summarize how
1624 > is applying all its <SPAN
1641 > Final results:
1645 -content-type-overwrite
1646 -crunch-client-header
1647 -crunch-if-none-match
1648 -crunch-incoming-cookies
1649 -crunch-outgoing-cookies
1650 -crunch-server-header
1651 +deanimate-gifs {last}
1652 -downgrade-http-version
1654 +filter {js-annoyances}
1655 +filter {html-annoyances}
1656 +filter {refresh-tags}
1657 +filter {unsolicited-popups}
1658 +filter {img-reorder}
1659 +filter {banners-by-size}
1661 +filter {jumping-windows}
1662 +filter {ie-exploits}
1663 -filter-client-headers
1664 -filter-server-headers
1666 -handle-as-empty-document
1668 -hide-accept-language
1669 -hide-content-disposition
1670 +hide-forwarded-for-headers
1671 +hide-from-header {block}
1672 -hide-if-modified-since
1673 +hide-referrer {forge}
1678 -overwrite-last-modified
1679 +prevent-compression
1683 -session-cookies-only
1684 +set-image-blocker {pattern}
1685 -treat-forbidden-connects-like-blocks </PRE
1691 > Notice the only difference here to the previous listing, is to
1694 >"fast-redirects"</SPAN
1697 >"session-cookies-only"</SPAN
1699 which are activated specifically for this site in our configuration,
1700 and thus show in the <SPAN
1702 >"Final Results"</SPAN
1705 > Now another example, <SPAN
1707 >"ad.doubleclick.net"</SPAN
1718 > { +block +handle-as-image }
1721 { +block +handle-as-image }
1724 { +block +handle-as-image }
1725 .doubleclick.net</PRE
1731 > We'll just show the interesting part here, the explicit matches. It is
1732 matched three different times. Each as an <SPAN
1734 >"+block +handle-as-image"</SPAN
1736 which is the expanded form of one of our aliases that had been defined as:
1739 >"+imageblock"</SPAN
1741 HREF="actions-file.html#ALIASES"
1747 the first section of the actions file and typically used to combine more
1748 than one action.)</P
1750 > Any one of these would have done the trick and blocked this as an unwanted
1751 image. This is unnecessarily redundant since the last case effectively
1752 would also cover the first. No point in taking chances with these guys
1753 though ;-) Note that if you want an ad or obnoxious
1754 URL to be invisible, it should be defined as <SPAN
1756 >"ad.doubleclick.net"</SPAN
1758 is done here -- as both a <A
1759 HREF="actions-file.html#BLOCK"
1773 HREF="actions-file.html#HANDLE-AS-IMAGE"
1776 >"+handle-as-image"</SPAN
1779 The custom alias <SPAN
1781 >"+imageblock"</SPAN
1782 > just simplifies the process and make
1783 it more readable.</P
1785 > One last example. Let's try <SPAN
1787 >"http://www.example.net/adsl/HOWTO/"</SPAN
1789 This one is giving us problems. We are getting a blank page. Hmmm ...</P
1799 > Matches for http://www.example.net/adsl/HOWTO/:
1801 In file: default.action <SPAN
1811 -content-type-overwrite
1812 -crunch-client-header
1813 -crunch-if-none-match
1814 -crunch-incoming-cookies
1815 -crunch-outgoing-cookies
1816 -crunch-server-header
1818 -downgrade-http-version
1819 +fast-redirects{check-decoded-url}
1820 +filter{html-annoyances}
1821 +filter{js-annoyances}
1822 +filter{kill-popups}
1825 +filter{banners-by-size}
1828 -filter-client-headers
1829 -filter-server-headers
1831 -handle-as-empty-document
1833 -hide-accept-language
1834 -hide-content-disposition
1835 +hide-forwarded-for-headers
1836 +hide-from-header{block}
1837 +hide-referer{forge}
1841 -overwrite-last-modified
1842 +prevent-compression
1846 +session-cookies-only
1847 +set-image-blocker{blank}
1848 -treat-forbidden-connects-like-blocks }
1851 { +block +handle-as-image }
1865 configuration! But we did not want this at all! Now we see why we get the
1866 blank page. We could now add a new action below this that explicitly
1880 > in them (remember, last match in the configuration wins).
1881 There are various ways to handle such exceptions. Example:</P
1898 > Now the page displays ;-) Be sure to flush your browser's caches when
1899 making such changes. Or, try using <TT
1904 > But now what about a situation where we get no explicit matches like
1915 > { +block +handle-as-image }
1922 > That actually was very telling and pointed us quickly to where the problem
1923 was. If you don't get this kind of match, then it means one of the default
1924 rules in the first section is causing the problem. This would require some
1925 guesswork, and maybe a little trial and error to isolate the offending rule.
1926 One likely cause would be one of the <SPAN
1930 tend to be harder to troubleshoot. Try adding the URL for the site to one of
1931 aliases that turn off <SPAN
1946 .worldpay.com # for quietpc.com
1964 >"{ -filter -session-cookies-only }"</SPAN
1966 Or you could do your own exception to negate filtering: </P
1983 > This would turn off all filtering for that site. This would probably be most
1984 appropriately put in <TT
1990 > Images that are inexplicably being blocked, may well be hitting the
1993 >"+filter{banners-by-size}"</SPAN
1994 > rule, which assumes
1995 that images of certain sizes are ad banners (works well most of the time
1996 since these tend to be standardized).</P
2001 > is an alias that disables most actions. This can be
2002 used as a last resort for problem sites. Remember to flush caches! If this
2003 still does not work, you will have to go through the remaining actions one by
2004 one to find which one(s) is causing the problem.</P
2012 SUMMARY="Footer navigation table"