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mpdudempdude
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Work around a (suspected) regression in libxml2 2.9.1 -> 2.9.2
In libxml 2.9.1 -> 2.9.2, a change was made to fix the handling of URIs with rootless paths ([initial report](https://bugzilla.gnome.org/show_bug.cgi?id=731063), [initial fix](https://git.gnome.org/browse/libxml2/commit/?id=8eb55d782a2b9afacc7938694891cc6fad7b42a5), [follow-up patch](https://git.gnome.org/browse/libxml2/commit/uri.c?id=beb7281055dbf0ed4d041022a67c6c5cfd126f25)). However, there still seems to be a bug with regard to how relative URIs are resolved when XML catalogs are processed. In particular, when installing (for example) the Debian `w3c-dtd-xhtml` package to provide a local cached copy of the XHTML DTD, libxml will correctly follow references to other catalog files as long as they are provided as absoulte `file://` URLs. But once it reaches `file:///usr/share/xml/xhtml/schema/dtd/1.0/catalog.xml`, additional references use relative URIs like `uri="xhtml1-strict.dtd"`. libxml will resolve this as `file:/usr/share/xml/xhtml/schema/dtd/1.0/xhtml1-strict.dtd` with a single leading slash only. This URL is subsequently used as a file system path, fails during a `stat()` call and will make PHP return an error message like `failed to load external entity "file:/usr/share/xml/xhtml/schema/dtd/1.0/xhtml1-strict.dtd"`. An earlier report of this problem can be found on the [libxml mailing list](https://mail.gnome.org/archives/xml/2014-December/msg00000.html). A second mail to this list is currently awaiting moderation and will hopefully become available in the [November 2016 archive](https://mail.gnome.org/archives/xml/2016-November/date.html#00000). As a workaround (and to make us somewhat independent of the exact libxml version installed on the underlying OS), we're including the four DTD and entity definition files relevant for `XHTML 1.0 Strict` in this repository and using a custom libxml entity loader in PHP userland to load these files. Note that this change effectively cuts out XML catalog support in libxml when used from PHP. It may cause unexpected side effects as only one external entity loader can seemingly be registered. Another approach we've tried was to come up with a custom XML catalog like ``` <?xml version="1.0"?> <!DOCTYPE catalog PUBLIC "-//OASIS//DTD Entity Resolution XML Catalog V1.0//EN" "http://www.oasis-open.org/committees/entity/release/1.0/catalog.dtd"> <catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog"> <public publicId="-//W3C//DTD XHTML 1.0 Strict//EN" uri="xhtml1-strict.dtd" /> <public publicId="-//W3C//ENTITIES Latin 1 for XHTML//EN" uri="xhtml-lat1.ent" /> <public publicId="-//W3C//ENTITIES Symbols for XHTML//EN" uri="xhtml-symbol.ent" /> <public publicId="-//W3C//ENTITIES Special for XHTML//EN" uri="xhtml-special.ent" /> </catalog> ``` When pointing to this file using the `XML_CATALOG_FILES` environment variable, file resolution will work because no `file://` based URLs are ever introduced during the resolution process. The difficulty, however, is to set this environment variable early enough: It seems the setting is read during libxml initialization while PHP starts up, so a simple `putenv()` from PHP comes too late. When running PHP as an Apache module, the environment variable has to be passed when starting Apache (`/etc/apache2/envvars`, for example), not from within virtual host definitions (`SetEnv`). This makes it hard to install/maintain the necessary setting and affects catalog processing at a lower (system-wide) level, which is why we abandoned it.
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‎src/Webfactory/Dom/XHTML10ParsingHelper.php‎

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namespace Webfactory\Dom;
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class XHTML10ParsingHelper extends HTMLParsingHelper {
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class XHTML10ParsingHelper extends HTMLParsingHelper
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{
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public function __construct()
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{
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libxml_set_external_entity_loader(function ($public, $system, $context) {
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$catalogDir = __DIR__ . '/../../../xml-catalog/';
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switch ($public) {
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case '-//W3C//DTD XHTML 1.0 Strict//EN':
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return $catalogDir . 'xhtml1-strict.dtd';
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case '-//W3C//ENTITIES Latin 1 for XHTML//EN':
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return $catalogDir . 'xhtml-lat1.ent';
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case '-//W3C//ENTITIES Symbols for XHTML//EN':
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return $catalogDir . 'xhtml-symbol.ent';
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case '-//W3C//ENTITIES Special for XHTML//EN':
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return $catalogDir . 'xhtml-special.ent';
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default:
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return $system;
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}
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});
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}
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protected function wrapFragment($fragment, $declaredNamespaces)
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{
@@ -19,5 +38,4 @@ protected function wrapFragment($fragment, $declaredNamespaces)
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$declaredNamespaces
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);
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}
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}

‎xml-catalog/xhtml-lat1.ent‎

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<!-- Portions (C) International Organization for Standardization 1986
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Permission to copy in any form is granted for use with
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conforming SGML systems and applications as defined in
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ISO 8879, provided this notice is included in all copies.
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-->
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<!-- Character entity set. Typical invocation:
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<!ENTITY % HTMLlat1 PUBLIC
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"-//W3C//ENTITIES Latin 1 for XHTML//EN"
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"http://www.w3.org/TR/xhtml1/DTD/xhtml-lat1.ent">
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%HTMLlat1;
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-->
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<!ENTITY nbsp "&#160;"> <!-- no-break space = non-breaking space,
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U+00A0 ISOnum -->
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<!ENTITY iexcl "&#161;"> <!-- inverted exclamation mark, U+00A1 ISOnum -->
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<!ENTITY cent "&#162;"> <!-- cent sign, U+00A2 ISOnum -->
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<!ENTITY pound "&#163;"> <!-- pound sign, U+00A3 ISOnum -->
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<!ENTITY curren "&#164;"> <!-- currency sign, U+00A4 ISOnum -->
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<!ENTITY yen "&#165;"> <!-- yen sign = yuan sign, U+00A5 ISOnum -->
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<!ENTITY brvbar "&#166;"> <!-- broken bar = broken vertical bar,
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U+00A6 ISOnum -->
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<!ENTITY sect "&#167;"> <!-- section sign, U+00A7 ISOnum -->
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<!ENTITY uml "&#168;"> <!-- diaeresis = spacing diaeresis,
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U+00A8 ISOdia -->
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<!ENTITY copy "&#169;"> <!-- copyright sign, U+00A9 ISOnum -->
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<!ENTITY ordf "&#170;"> <!-- feminine ordinal indicator, U+00AA ISOnum -->
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<!ENTITY laquo "&#171;"> <!-- left-pointing double angle quotation mark
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= left pointing guillemet, U+00AB ISOnum -->
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<!ENTITY not "&#172;"> <!-- not sign = angled dash,
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U+00AC ISOnum -->
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<!ENTITY shy "&#173;"> <!-- soft hyphen = discretionary hyphen,
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U+00AD ISOnum -->
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<!ENTITY reg "&#174;"> <!-- registered sign = registered trade mark sign,
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U+00AE ISOnum -->
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<!ENTITY macr "&#175;"> <!-- macron = spacing macron = overline
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= APL overbar, U+00AF ISOdia -->
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<!ENTITY deg "&#176;"> <!-- degree sign, U+00B0 ISOnum -->
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<!ENTITY plusmn "&#177;"> <!-- plus-minus sign = plus-or-minus sign,
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U+00B1 ISOnum -->
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<!ENTITY sup2 "&#178;"> <!-- superscript two = superscript digit two
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= squared, U+00B2 ISOnum -->
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<!ENTITY sup3 "&#179;"> <!-- superscript three = superscript digit three
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= cubed, U+00B3 ISOnum -->
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<!ENTITY acute "&#180;"> <!-- acute accent = spacing acute,
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U+00B4 ISOdia -->
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<!ENTITY micro "&#181;"> <!-- micro sign, U+00B5 ISOnum -->
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<!ENTITY para "&#182;"> <!-- pilcrow sign = paragraph sign,
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U+00B6 ISOnum -->
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<!ENTITY middot "&#183;"> <!-- middle dot = Georgian comma
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= Greek middle dot, U+00B7 ISOnum -->
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<!ENTITY cedil "&#184;"> <!-- cedilla = spacing cedilla, U+00B8 ISOdia -->
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<!ENTITY sup1 "&#185;"> <!-- superscript one = superscript digit one,
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U+00B9 ISOnum -->
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<!ENTITY ordm "&#186;"> <!-- masculine ordinal indicator,
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U+00BA ISOnum -->
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<!ENTITY raquo "&#187;"> <!-- right-pointing double angle quotation mark
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= right pointing guillemet, U+00BB ISOnum -->
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<!ENTITY frac14 "&#188;"> <!-- vulgar fraction one quarter
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= fraction one quarter, U+00BC ISOnum -->
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<!ENTITY frac12 "&#189;"> <!-- vulgar fraction one half
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= fraction one half, U+00BD ISOnum -->
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<!ENTITY frac34 "&#190;"> <!-- vulgar fraction three quarters
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= fraction three quarters, U+00BE ISOnum -->
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<!ENTITY iquest "&#191;"> <!-- inverted question mark
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= turned question mark, U+00BF ISOnum -->
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<!ENTITY Agrave "&#192;"> <!-- latin capital letter A with grave
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= latin capital letter A grave,
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U+00C0 ISOlat1 -->
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<!ENTITY Aacute "&#193;"> <!-- latin capital letter A with acute,
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U+00C1 ISOlat1 -->
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<!ENTITY Acirc "&#194;"> <!-- latin capital letter A with circumflex,
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U+00C2 ISOlat1 -->
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<!ENTITY Atilde "&#195;"> <!-- latin capital letter A with tilde,
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U+00C3 ISOlat1 -->
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<!ENTITY Auml "&#196;"> <!-- latin capital letter A with diaeresis,
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U+00C4 ISOlat1 -->
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<!ENTITY Aring "&#197;"> <!-- latin capital letter A with ring above
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= latin capital letter A ring,
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U+00C5 ISOlat1 -->
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<!ENTITY AElig "&#198;"> <!-- latin capital letter AE
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= latin capital ligature AE,
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U+00C6 ISOlat1 -->
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<!ENTITY Ccedil "&#199;"> <!-- latin capital letter C with cedilla,
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U+00C7 ISOlat1 -->
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<!ENTITY Egrave "&#200;"> <!-- latin capital letter E with grave,
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U+00C8 ISOlat1 -->
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<!ENTITY Eacute "&#201;"> <!-- latin capital letter E with acute,
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U+00C9 ISOlat1 -->
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<!ENTITY Ecirc "&#202;"> <!-- latin capital letter E with circumflex,
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U+00CA ISOlat1 -->
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<!ENTITY Euml "&#203;"> <!-- latin capital letter E with diaeresis,
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U+00CB ISOlat1 -->
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<!ENTITY Igrave "&#204;"> <!-- latin capital letter I with grave,
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U+00CC ISOlat1 -->
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<!ENTITY Iacute "&#205;"> <!-- latin capital letter I with acute,
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U+00CD ISOlat1 -->
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<!ENTITY Icirc "&#206;"> <!-- latin capital letter I with circumflex,
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U+00CE ISOlat1 -->
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<!ENTITY Iuml "&#207;"> <!-- latin capital letter I with diaeresis,
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U+00CF ISOlat1 -->
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<!ENTITY ETH "&#208;"> <!-- latin capital letter ETH, U+00D0 ISOlat1 -->
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<!ENTITY Ntilde "&#209;"> <!-- latin capital letter N with tilde,
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U+00D1 ISOlat1 -->
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<!ENTITY Ograve "&#210;"> <!-- latin capital letter O with grave,
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U+00D2 ISOlat1 -->
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<!ENTITY Oacute "&#211;"> <!-- latin capital letter O with acute,
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U+00D3 ISOlat1 -->
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<!ENTITY Ocirc "&#212;"> <!-- latin capital letter O with circumflex,
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U+00D4 ISOlat1 -->
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<!ENTITY Otilde "&#213;"> <!-- latin capital letter O with tilde,
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U+00D5 ISOlat1 -->
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<!ENTITY Ouml "&#214;"> <!-- latin capital letter O with diaeresis,
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U+00D6 ISOlat1 -->
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<!ENTITY times "&#215;"> <!-- multiplication sign, U+00D7 ISOnum -->
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<!ENTITY Oslash "&#216;"> <!-- latin capital letter O with stroke
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= latin capital letter O slash,
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U+00D8 ISOlat1 -->
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<!ENTITY Ugrave "&#217;"> <!-- latin capital letter U with grave,
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U+00D9 ISOlat1 -->
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<!ENTITY Uacute "&#218;"> <!-- latin capital letter U with acute,
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U+00DA ISOlat1 -->
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<!ENTITY Ucirc "&#219;"> <!-- latin capital letter U with circumflex,
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U+00DB ISOlat1 -->
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<!ENTITY Uuml "&#220;"> <!-- latin capital letter U with diaeresis,
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U+00DC ISOlat1 -->
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<!ENTITY Yacute "&#221;"> <!-- latin capital letter Y with acute,
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U+00DD ISOlat1 -->
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<!ENTITY THORN "&#222;"> <!-- latin capital letter THORN,
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U+00DE ISOlat1 -->
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<!ENTITY szlig "&#223;"> <!-- latin small letter sharp s = ess-zed,
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U+00DF ISOlat1 -->
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<!ENTITY agrave "&#224;"> <!-- latin small letter a with grave
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= latin small letter a grave,
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U+00E0 ISOlat1 -->
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<!ENTITY aacute "&#225;"> <!-- latin small letter a with acute,
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U+00E1 ISOlat1 -->
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<!ENTITY acirc "&#226;"> <!-- latin small letter a with circumflex,
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U+00E2 ISOlat1 -->
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<!ENTITY atilde "&#227;"> <!-- latin small letter a with tilde,
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U+00E3 ISOlat1 -->
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<!ENTITY auml "&#228;"> <!-- latin small letter a with diaeresis,
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U+00E4 ISOlat1 -->
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<!ENTITY aring "&#229;"> <!-- latin small letter a with ring above
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= latin small letter a ring,
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U+00E5 ISOlat1 -->
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<!ENTITY aelig "&#230;"> <!-- latin small letter ae
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= latin small ligature ae, U+00E6 ISOlat1 -->
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<!ENTITY ccedil "&#231;"> <!-- latin small letter c with cedilla,
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U+00E7 ISOlat1 -->
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<!ENTITY egrave "&#232;"> <!-- latin small letter e with grave,
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U+00E8 ISOlat1 -->
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<!ENTITY eacute "&#233;"> <!-- latin small letter e with acute,
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U+00E9 ISOlat1 -->
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<!ENTITY ecirc "&#234;"> <!-- latin small letter e with circumflex,
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U+00EA ISOlat1 -->
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<!ENTITY euml "&#235;"> <!-- latin small letter e with diaeresis,
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U+00EB ISOlat1 -->
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<!ENTITY igrave "&#236;"> <!-- latin small letter i with grave,
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U+00EC ISOlat1 -->
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<!ENTITY iacute "&#237;"> <!-- latin small letter i with acute,
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U+00ED ISOlat1 -->
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<!ENTITY icirc "&#238;"> <!-- latin small letter i with circumflex,
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U+00EE ISOlat1 -->
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<!ENTITY iuml "&#239;"> <!-- latin small letter i with diaeresis,
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U+00EF ISOlat1 -->
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<!ENTITY eth "&#240;"> <!-- latin small letter eth, U+00F0 ISOlat1 -->
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<!ENTITY ntilde "&#241;"> <!-- latin small letter n with tilde,
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U+00F1 ISOlat1 -->
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<!ENTITY ograve "&#242;"> <!-- latin small letter o with grave,
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U+00F2 ISOlat1 -->
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<!ENTITY oacute "&#243;"> <!-- latin small letter o with acute,
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U+00F3 ISOlat1 -->
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<!ENTITY ocirc "&#244;"> <!-- latin small letter o with circumflex,
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U+00F4 ISOlat1 -->
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<!ENTITY otilde "&#245;"> <!-- latin small letter o with tilde,
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U+00F5 ISOlat1 -->
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<!ENTITY ouml "&#246;"> <!-- latin small letter o with diaeresis,
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U+00F6 ISOlat1 -->
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<!ENTITY divide "&#247;"> <!-- division sign, U+00F7 ISOnum -->
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<!ENTITY oslash "&#248;"> <!-- latin small letter o with stroke,
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= latin small letter o slash,
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U+00F8 ISOlat1 -->
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<!ENTITY ugrave "&#249;"> <!-- latin small letter u with grave,
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U+00F9 ISOlat1 -->
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<!ENTITY uacute "&#250;"> <!-- latin small letter u with acute,
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U+00FA ISOlat1 -->
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<!ENTITY ucirc "&#251;"> <!-- latin small letter u with circumflex,
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U+00FB ISOlat1 -->
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<!ENTITY uuml "&#252;"> <!-- latin small letter u with diaeresis,
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U+00FC ISOlat1 -->
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<!ENTITY yacute "&#253;"> <!-- latin small letter y with acute,
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U+00FD ISOlat1 -->
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<!ENTITY thorn "&#254;"> <!-- latin small letter thorn,
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U+00FE ISOlat1 -->
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<!ENTITY yuml "&#255;"> <!-- latin small letter y with diaeresis,
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U+00FF ISOlat1 -->

‎xml-catalog/xhtml-special.ent‎

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<!-- Special characters for XHTML -->
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<!-- Character entity set. Typical invocation:
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<!ENTITY % HTMLspecial PUBLIC
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"-//W3C//ENTITIES Special for XHTML//EN"
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"http://www.w3.org/TR/xhtml1/DTD/xhtml-special.ent">
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%HTMLspecial;
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-->
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<!-- Portions (C) International Organization for Standardization 1986:
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Permission to copy in any form is granted for use with
12+
conforming SGML systems and applications as defined in
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ISO 8879, provided this notice is included in all copies.
14+
-->
15+
16+
<!-- Relevant ISO entity set is given unless names are newly introduced.
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New names (i.e., not in ISO 8879 list) do not clash with any
18+
existing ISO 8879 entity names. ISO 10646 character numbers
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are given for each character, in hex. values are decimal
20+
conversions of the ISO 10646 values and refer to the document
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character set. Names are Unicode names.
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-->
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<!-- C0 Controls and Basic Latin -->
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<!ENTITY quot "&#34;"> <!-- quotation mark, U+0022 ISOnum -->
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<!ENTITY amp "&#38;#38;"> <!-- ampersand, U+0026 ISOnum -->
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<!ENTITY lt "&#38;#60;"> <!-- less-than sign, U+003C ISOnum -->
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<!ENTITY gt "&#62;"> <!-- greater-than sign, U+003E ISOnum -->
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<!ENTITY apos "&#39;"> <!-- apostrophe = APL quote, U+0027 ISOnum -->
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<!-- Latin Extended-A -->
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<!ENTITY OElig "&#338;"> <!-- latin capital ligature OE,
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U+0152 ISOlat2 -->
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<!ENTITY oelig "&#339;"> <!-- latin small ligature oe, U+0153 ISOlat2 -->
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<!-- ligature is a misnomer, this is a separate character in some languages -->
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<!ENTITY Scaron "&#352;"> <!-- latin capital letter S with caron,
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U+0160 ISOlat2 -->
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<!ENTITY scaron "&#353;"> <!-- latin small letter s with caron,
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U+0161 ISOlat2 -->
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<!ENTITY Yuml "&#376;"> <!-- latin capital letter Y with diaeresis,
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U+0178 ISOlat2 -->
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<!-- Spacing Modifier Letters -->
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<!ENTITY circ "&#710;"> <!-- modifier letter circumflex accent,
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U+02C6 ISOpub -->
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<!ENTITY tilde "&#732;"> <!-- small tilde, U+02DC ISOdia -->
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<!-- General Punctuation -->
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<!ENTITY ensp "&#8194;"> <!-- en space, U+2002 ISOpub -->
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<!ENTITY emsp "&#8195;"> <!-- em space, U+2003 ISOpub -->
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<!ENTITY thinsp "&#8201;"> <!-- thin space, U+2009 ISOpub -->
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<!ENTITY zwnj "&#8204;"> <!-- zero width non-joiner,
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U+200C NEW RFC 2070 -->
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<!ENTITY zwj "&#8205;"> <!-- zero width joiner, U+200D NEW RFC 2070 -->
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<!ENTITY lrm "&#8206;"> <!-- left-to-right mark, U+200E NEW RFC 2070 -->
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<!ENTITY rlm "&#8207;"> <!-- right-to-left mark, U+200F NEW RFC 2070 -->
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<!ENTITY ndash "&#8211;"> <!-- en dash, U+2013 ISOpub -->
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<!ENTITY mdash "&#8212;"> <!-- em dash, U+2014 ISOpub -->
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<!ENTITY lsquo "&#8216;"> <!-- left single quotation mark,
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U+2018 ISOnum -->
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<!ENTITY rsquo "&#8217;"> <!-- right single quotation mark,
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U+2019 ISOnum -->
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<!ENTITY sbquo "&#8218;"> <!-- single low-9 quotation mark, U+201A NEW -->
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<!ENTITY ldquo "&#8220;"> <!-- left double quotation mark,
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U+201C ISOnum -->
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<!ENTITY rdquo "&#8221;"> <!-- right double quotation mark,
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U+201D ISOnum -->
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<!ENTITY bdquo "&#8222;"> <!-- double low-9 quotation mark, U+201E NEW -->
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<!ENTITY dagger "&#8224;"> <!-- dagger, U+2020 ISOpub -->
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<!ENTITY Dagger "&#8225;"> <!-- double dagger, U+2021 ISOpub -->
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<!ENTITY permil "&#8240;"> <!-- per mille sign, U+2030 ISOtech -->
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<!ENTITY lsaquo "&#8249;"> <!-- single left-pointing angle quotation mark,
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U+2039 ISO proposed -->
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<!-- lsaquo is proposed but not yet ISO standardized -->
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<!ENTITY rsaquo "&#8250;"> <!-- single right-pointing angle quotation mark,
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U+203A ISO proposed -->
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<!-- rsaquo is proposed but not yet ISO standardized -->
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<!-- Currency Symbols -->
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<!ENTITY euro "&#8364;"> <!-- euro sign, U+20AC NEW -->

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