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[o]" accesskey="o"><span class="vector-icon mw-ui-icon-logIn mw-ui-icon-wikimedia-logIn"></span> <span>Log in</span></a></li> </ul> </div> </div> <div id="p-user-menu-anon-editor" class="vector-menu mw-portlet mw-portlet-user-menu-anon-editor" > <div class="vector-menu-heading"> Pages for logged out editors <a href="/wiki/Help:Introduction" aria-label="Learn more about editing"><span>learn more</span></a> </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="pt-anoncontribs" class="mw-list-item"><a href="/wiki/Special:MyContributions" title="A list of edits made from this IP address [y]" accesskey="y"><span>Contributions</span></a></li><li id="pt-anontalk" class="mw-list-item"><a href="/wiki/Special:MyTalk" title="Discussion about edits from this IP address [n]" accesskey="n"><span>Talk</span></a></li> </ul> </div> </div> </div> </div> </nav> </div> </header> </div> <div class="mw-page-container"> <div class="mw-page-container-inner"> <div class="vector-sitenotice-container"> <div id="siteNotice"></div> </div> <div class="vector-column-start"> <div class="vector-main-menu-container"> <div id="mw-navigation"> <nav id="mw-panel" class="vector-main-menu-landmark" aria-label="Site"> <div id="vector-main-menu-pinned-container" class="vector-pinned-container"> </div> </nav> </div> </div> <div class="vector-sticky-pinned-container"> <nav id="mw-panel-toc" aria-label="Contents" data-event-name="ui.sidebar-toc" class="mw-table-of-contents-container vector-toc-landmark"> <div id="vector-toc-pinned-container" class="vector-pinned-container"> <div id="vector-toc" class="vector-toc vector-pinnable-element"> <div class="vector-pinnable-header vector-toc-pinnable-header vector-pinnable-header-pinned" data-feature-name="toc-pinned" data-pinnable-element-id="vector-toc" > <h2 class="vector-pinnable-header-label">Contents</h2> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-pin-button" data-event-name="pinnable-header.vector-toc.pin">move to sidebar</button> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-unpin-button" data-event-name="pinnable-header.vector-toc.unpin">hide</button> </div> <ul class="vector-toc-contents" id="mw-panel-toc-list"> <li id="toc-mw-content-text" class="vector-toc-list-item vector-toc-level-1"> <a href="#" class="vector-toc-link"> <div class="vector-toc-text">(Top)</div> </a> </li> <li id="toc-CDATA_sections_in_XML" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#CDATA_sections_in_XML"> <div class="vector-toc-text"> <span class="vector-toc-numb">1</span> <span>CDATA sections in XML</span> </div> </a> <button aria-controls="toc-CDATA_sections_in_XML-sublist" class="cdx-button cdx-button--weight-quiet cdx-button--icon-only vector-toc-toggle"> <span class="vector-icon mw-ui-icon-wikimedia-expand"></span> <span>Toggle CDATA sections in XML subsection</span> </button> <ul id="toc-CDATA_sections_in_XML-sublist" class="vector-toc-list"> <li id="toc-Syntax_and_interpretation" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Syntax_and_interpretation"> <div class="vector-toc-text"> <span class="vector-toc-numb">1.1</span> <span>Syntax and interpretation</span> </div> </a> <ul id="toc-Syntax_and_interpretation-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Uses_of_CDATA_sections" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Uses_of_CDATA_sections"> <div class="vector-toc-text"> <span class="vector-toc-numb">1.2</span> <span>Uses of CDATA sections</span> </div> </a> <ul id="toc-Uses_of_CDATA_sections-sublist" class="vector-toc-list"> <li id="toc-Nesting" class="vector-toc-list-item vector-toc-level-3"> <a class="vector-toc-link" href="#Nesting"> <div class="vector-toc-text"> <span class="vector-toc-numb">1.2.1</span> <span>Nesting</span> </div> </a> <ul id="toc-Nesting-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Issues_with_encoding" class="vector-toc-list-item vector-toc-level-3"> <a class="vector-toc-link" href="#Issues_with_encoding"> <div class="vector-toc-text"> <span class="vector-toc-numb">1.2.2</span> <span>Issues with encoding</span> </div> </a> <ul id="toc-Issues_with_encoding-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> </ul> </li> <li id="toc-Use_of_CDATA_in_program_output" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Use_of_CDATA_in_program_output"> <div class="vector-toc-text"> <span class="vector-toc-numb">2</span> <span>Use of CDATA in program output</span> </div> </a> <ul id="toc-Use_of_CDATA_in_program_output-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-CDATA_in_DTDs" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#CDATA_in_DTDs"> <div class="vector-toc-text"> <span class="vector-toc-numb">3</span> <span>CDATA in DTDs</span> </div> </a> <button aria-controls="toc-CDATA_in_DTDs-sublist" class="cdx-button cdx-button--weight-quiet cdx-button--icon-only vector-toc-toggle"> <span class="vector-icon mw-ui-icon-wikimedia-expand"></span> <span>Toggle CDATA in DTDs subsection</span> </button> <ul id="toc-CDATA_in_DTDs-sublist" class="vector-toc-list"> <li id="toc-CDATA-type_attribute_value" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#CDATA-type_attribute_value"> <div class="vector-toc-text"> <span class="vector-toc-numb">3.1</span> <span>CDATA-type attribute value</span> </div> </a> <ul id="toc-CDATA-type_attribute_value-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-CDATA-type_entity" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#CDATA-type_entity"> <div class="vector-toc-text"> <span class="vector-toc-numb">3.2</span> <span>CDATA-type entity</span> </div> </a> <ul id="toc-CDATA-type_entity-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> <li id="toc-See_also" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#See_also"> <div class="vector-toc-text"> <span class="vector-toc-numb">4</span> <span>See also</span> </div> </a> <ul id="toc-See_also-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-References" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#References"> <div class="vector-toc-text"> <span class="vector-toc-numb">5</span> <span>References</span> </div> </a> <ul id="toc-References-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-External_links" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#External_links"> <div class="vector-toc-text"> <span class="vector-toc-numb">6</span> <span>External links</span> </div> </a> <ul id="toc-External_links-sublist" class="vector-toc-list"> </ul> </li> </ul> </div> </div> </nav> </div> </div> <div class="mw-content-container"> <main id="content" class="mw-body"> <header class="mw-body-header vector-page-titlebar"> <nav aria-label="Contents" class="vector-toc-landmark"> <div id="vector-page-titlebar-toc" class="vector-dropdown vector-page-titlebar-toc vector-button-flush-left" > <input type="checkbox" id="vector-page-titlebar-toc-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-page-titlebar-toc" class="vector-dropdown-checkbox " aria-label="Toggle the table of contents" > <label id="vector-page-titlebar-toc-label" for="vector-page-titlebar-toc-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only " aria-hidden="true" ><span class="vector-icon mw-ui-icon-listBullet mw-ui-icon-wikimedia-listBullet"></span> <span class="vector-dropdown-label-text">Toggle the table of contents</span> </label> <div class="vector-dropdown-content"> <div id="vector-page-titlebar-toc-unpinned-container" class="vector-unpinned-container"> </div> </div> </div> </nav> <h1 id="firstHeading" class="firstHeading mw-first-heading"><span class="mw-page-title-main">CDATA</span></h1> <div id="p-lang-btn" class="vector-dropdown mw-portlet mw-portlet-lang" > <input type="checkbox" id="p-lang-btn-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-p-lang-btn" class="vector-dropdown-checkbox mw-interlanguage-selector" aria-label="Go to an article in another language. Available in 8 languages" > <label id="p-lang-btn-label" for="p-lang-btn-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--action-progressive mw-portlet-lang-heading-8" aria-hidden="true" ><span class="vector-icon mw-ui-icon-language-progressive mw-ui-icon-wikimedia-language-progressive"></span> <span class="vector-dropdown-label-text">8 languages</span> </label> <div class="vector-dropdown-content"> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li class="interlanguage-link interwiki-ar mw-list-item"><a href="https://ar.wikipedia.org/wiki/%D8%A7%D9%84%D8%A8%D9%8A%D8%A7%D9%86%D8%A7%D8%AA_%D8%A7%D9%84%D8%AD%D8%B1%D9%81%D9%8A%D8%A9" title="البيانات الحرفية – Arabic" lang="ar" hreflang="ar" data-title="البيانات الحرفية" data-language-autonym="العربية" data-language-local-name="Arabic" class="interlanguage-link-target"><span>العربية</span></a></li><li class="interlanguage-link interwiki-de mw-list-item"><a href="https://de.wikipedia.org/wiki/CDATA" title="CDATA – German" lang="de" hreflang="de" data-title="CDATA" data-language-autonym="Deutsch" data-language-local-name="German" class="interlanguage-link-target"><span>Deutsch</span></a></li><li class="interlanguage-link interwiki-es mw-list-item"><a href="https://es.wikipedia.org/wiki/CDATA" title="CDATA – Spanish" lang="es" hreflang="es" data-title="CDATA" data-language-autonym="Español" data-language-local-name="Spanish" class="interlanguage-link-target"><span>Español</span></a></li><li class="interlanguage-link interwiki-eo mw-list-item"><a href="https://eo.wikipedia.org/wiki/CDATA" title="CDATA – Esperanto" lang="eo" hreflang="eo" data-title="CDATA" data-language-autonym="Esperanto" data-language-local-name="Esperanto" class="interlanguage-link-target"><span>Esperanto</span></a></li><li class="interlanguage-link interwiki-it mw-list-item"><a href="https://it.wikipedia.org/wiki/CDATA" title="CDATA – Italian" lang="it" hreflang="it" data-title="CDATA" data-language-autonym="Italiano" data-language-local-name="Italian" class="interlanguage-link-target"><span>Italiano</span></a></li><li class="interlanguage-link interwiki-ru mw-list-item"><a href="https://ru.wikipedia.org/wiki/CDATA" title="CDATA – Russian" lang="ru" hreflang="ru" data-title="CDATA" data-language-autonym="Русский" data-language-local-name="Russian" class="interlanguage-link-target"><span>Русский</span></a></li><li class="interlanguage-link interwiki-uk mw-list-item"><a href="https://uk.wikipedia.org/wiki/CDATA" title="CDATA – Ukrainian" lang="uk" hreflang="uk" data-title="CDATA" data-language-autonym="Українська" data-language-local-name="Ukrainian" class="interlanguage-link-target"><span>Українська</span></a></li><li class="interlanguage-link interwiki-zh mw-list-item"><a href="https://zh.wikipedia.org/wiki/CDATA" title="CDATA – Chinese" lang="zh" hreflang="zh" data-title="CDATA" data-language-autonym="中文" data-language-local-name="Chinese" class="interlanguage-link-target"><span>中文</span></a></li> </ul> <div class="after-portlet after-portlet-lang"><span class="wb-langlinks-edit wb-langlinks-link"><a href="https://www.wikidata.org/wiki/Special:EntityPage/Q357626#sitelinks-wikipedia" title="Edit interlanguage links" class="wbc-editpage">Edit links</a></span></div> </div> </div> </div> </header> <div class="vector-page-toolbar"> <div class="vector-page-toolbar-container"> <div id="left-navigation"> <nav aria-label="Namespaces"> <div id="p-associated-pages" class="vector-menu vector-menu-tabs mw-portlet mw-portlet-associated-pages" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="ca-nstab-main" class="selected vector-tab-noicon mw-list-item"><a href="/wiki/CDATA" title="View the content page [c]" accesskey="c"><span>Article</span></a></li><li id="ca-talk" class="vector-tab-noicon mw-list-item"><a href="/wiki/Talk:CDATA" rel="discussion" title="Discuss improvements to the content page [t]" accesskey="t"><span>Talk</span></a></li> </ul> </div> </div> <div id="vector-variants-dropdown" class="vector-dropdown emptyPortlet" > <input type="checkbox" id="vector-variants-dropdown-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-variants-dropdown" class="vector-dropdown-checkbox " aria-label="Change language variant" > <label id="vector-variants-dropdown-label" for="vector-variants-dropdown-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet" aria-hidden="true" ><span class="vector-dropdown-label-text">English</span> </label> <div class="vector-dropdown-content"> <div id="p-variants" class="vector-menu mw-portlet mw-portlet-variants emptyPortlet" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> </ul> </div> </div> </div> </div> </nav> </div> <div id="right-navigation" class="vector-collapsible"> <nav aria-label="Views"> <div id="p-views" class="vector-menu vector-menu-tabs mw-portlet mw-portlet-views" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="ca-view" class="selected vector-tab-noicon mw-list-item"><a href="/wiki/CDATA"><span>Read</span></a></li><li id="ca-edit" class="vector-tab-noicon mw-list-item"><a href="/w/index.php?title=CDATA&action=edit" title="Edit this page [e]" accesskey="e"><span>Edit</span></a></li><li id="ca-history" class="vector-tab-noicon mw-list-item"><a href="/w/index.php?title=CDATA&action=history" title="Past revisions of this page [h]" accesskey="h"><span>View history</span></a></li> </ul> </div> </div> </nav> <nav class="vector-page-tools-landmark" aria-label="Page tools"> <div id="vector-page-tools-dropdown" class="vector-dropdown vector-page-tools-dropdown" > <input type="checkbox" id="vector-page-tools-dropdown-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-page-tools-dropdown" class="vector-dropdown-checkbox " aria-label="Tools" > <label id="vector-page-tools-dropdown-label" for="vector-page-tools-dropdown-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet" aria-hidden="true" ><span class="vector-dropdown-label-text">Tools</span> </label> <div class="vector-dropdown-content"> <div id="vector-page-tools-unpinned-container" class="vector-unpinned-container"> <div id="vector-page-tools" class="vector-page-tools vector-pinnable-element"> <div class="vector-pinnable-header vector-page-tools-pinnable-header vector-pinnable-header-unpinned" data-feature-name="page-tools-pinned" data-pinnable-element-id="vector-page-tools" data-pinned-container-id="vector-page-tools-pinned-container" data-unpinned-container-id="vector-page-tools-unpinned-container" > <div class="vector-pinnable-header-label">Tools</div> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-pin-button" data-event-name="pinnable-header.vector-page-tools.pin">move to sidebar</button> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-unpin-button" data-event-name="pinnable-header.vector-page-tools.unpin">hide</button> </div> <div id="p-cactions" class="vector-menu mw-portlet mw-portlet-cactions emptyPortlet vector-has-collapsible-items" title="More options" > <div class="vector-menu-heading"> Actions </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="ca-more-view" class="selected vector-more-collapsible-item mw-list-item"><a href="/wiki/CDATA"><span>Read</span></a></li><li id="ca-more-edit" class="vector-more-collapsible-item mw-list-item"><a href="/w/index.php?title=CDATA&action=edit" title="Edit this page [e]" accesskey="e"><span>Edit</span></a></li><li id="ca-more-history" class="vector-more-collapsible-item mw-list-item"><a href="/w/index.php?title=CDATA&action=history"><span>View history</span></a></li> </ul> </div> </div> <div id="p-tb" class="vector-menu mw-portlet mw-portlet-tb" > <div class="vector-menu-heading"> General </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="t-whatlinkshere" class="mw-list-item"><a href="/wiki/Special:WhatLinksHere/CDATA" title="List of all English Wikipedia pages containing links to this page [j]" accesskey="j"><span>What links here</span></a></li><li id="t-recentchangeslinked" class="mw-list-item"><a href="/wiki/Special:RecentChangesLinked/CDATA" rel="nofollow" title="Recent changes in pages linked from this page [k]" accesskey="k"><span>Related changes</span></a></li><li id="t-upload" class="mw-list-item"><a href="/wiki/Wikipedia:File_Upload_Wizard" title="Upload files [u]" accesskey="u"><span>Upload file</span></a></li><li id="t-specialpages" class="mw-list-item"><a href="/wiki/Special:SpecialPages" title="A list of all special pages [q]" accesskey="q"><span>Special pages</span></a></li><li id="t-permalink" class="mw-list-item"><a href="/w/index.php?title=CDATA&oldid=1181939799" title="Permanent link to this revision of this page"><span>Permanent link</span></a></li><li id="t-info" class="mw-list-item"><a href="/w/index.php?title=CDATA&action=info" title="More information about this page"><span>Page information</span></a></li><li id="t-cite" class="mw-list-item"><a href="/w/index.php?title=Special:CiteThisPage&page=CDATA&id=1181939799&wpFormIdentifier=titleform" title="Information on how to cite this page"><span>Cite this page</span></a></li><li id="t-urlshortener" class="mw-list-item"><a href="/w/index.php?title=Special:UrlShortener&url=https%3A%2F%2Fen.wikipedia.org%2Fwiki%2FCDATA"><span>Get shortened URL</span></a></li><li id="t-urlshortener-qrcode" class="mw-list-item"><a href="/w/index.php?title=Special:QrCode&url=https%3A%2F%2Fen.wikipedia.org%2Fwiki%2FCDATA"><span>Download QR code</span></a></li> </ul> </div> </div> <div id="p-coll-print_export" class="vector-menu mw-portlet mw-portlet-coll-print_export" > <div class="vector-menu-heading"> Print/export </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="coll-download-as-rl" class="mw-list-item"><a href="/w/index.php?title=Special:DownloadAsPdf&page=CDATA&action=show-download-screen" title="Download this page as a PDF file"><span>Download as PDF</span></a></li><li id="t-print" class="mw-list-item"><a href="/w/index.php?title=CDATA&printable=yes" title="Printable version of this page [p]" accesskey="p"><span>Printable version</span></a></li> </ul> </div> </div> <div id="p-wikibase-otherprojects" class="vector-menu mw-portlet mw-portlet-wikibase-otherprojects" > <div class="vector-menu-heading"> In other projects </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="t-wikibase" class="wb-otherproject-link wb-otherproject-wikibase-dataitem mw-list-item"><a href="https://www.wikidata.org/wiki/Special:EntityPage/Q357626" title="Structured data on this page hosted by Wikidata [g]" accesskey="g"><span>Wikidata item</span></a></li> </ul> </div> </div> </div> </div> </div> </div> </nav> </div> </div> </div> <div class="vector-column-end"> <div class="vector-sticky-pinned-container"> <nav class="vector-page-tools-landmark" aria-label="Page tools"> <div id="vector-page-tools-pinned-container" class="vector-pinned-container"> </div> </nav> <nav class="vector-appearance-landmark" aria-label="Appearance"> <div id="vector-appearance-pinned-container" class="vector-pinned-container"> <div id="vector-appearance" class="vector-appearance vector-pinnable-element"> <div class="vector-pinnable-header vector-appearance-pinnable-header vector-pinnable-header-pinned" data-feature-name="appearance-pinned" data-pinnable-element-id="vector-appearance" data-pinned-container-id="vector-appearance-pinned-container" data-unpinned-container-id="vector-appearance-unpinned-container" > <div class="vector-pinnable-header-label">Appearance</div> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-pin-button" data-event-name="pinnable-header.vector-appearance.pin">move to sidebar</button> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-unpin-button" data-event-name="pinnable-header.vector-appearance.unpin">hide</button> </div> </div> </div> </nav> </div> </div> <div id="bodyContent" class="vector-body" aria-labelledby="firstHeading" data-mw-ve-target-container> <div class="vector-body-before-content"> <div class="mw-indicators"> </div> <div id="siteSub" class="noprint">From Wikipedia, the free encyclopedia</div> </div> <div id="contentSub"><div id="mw-content-subtitle"></div></div> <div id="mw-content-text" class="mw-body-content"><div class="mw-content-ltr mw-parser-output" lang="en" dir="ltr"><div class="shortdescription nomobile noexcerpt noprint searchaux" style="display:none">Section delimiter in the markup languages SGML and XML</div> <style data-mw-deduplicate="TemplateStyles:r1251242444">.mw-parser-output .ambox{border:1px solid #a2a9b1;border-left:10px solid #36c;background-color:#fbfbfb;box-sizing:border-box}.mw-parser-output .ambox+link+.ambox,.mw-parser-output .ambox+link+style+.ambox,.mw-parser-output .ambox+link+link+.ambox,.mw-parser-output .ambox+.mw-empty-elt+link+.ambox,.mw-parser-output .ambox+.mw-empty-elt+link+style+.ambox,.mw-parser-output .ambox+.mw-empty-elt+link+link+.ambox{margin-top:-1px}html body.mediawiki .mw-parser-output .ambox.mbox-small-left{margin:4px 1em 4px 0;overflow:hidden;width:238px;border-collapse:collapse;font-size:88%;line-height:1.25em}.mw-parser-output .ambox-speedy{border-left:10px solid #b32424;background-color:#fee7e6}.mw-parser-output .ambox-delete{border-left:10px solid #b32424}.mw-parser-output .ambox-content{border-left:10px solid #f28500}.mw-parser-output .ambox-style{border-left:10px solid #fc3}.mw-parser-output .ambox-move{border-left:10px solid #9932cc}.mw-parser-output .ambox-protection{border-left:10px solid #a2a9b1}.mw-parser-output .ambox .mbox-text{border:none;padding:0.25em 0.5em;width:100%}.mw-parser-output .ambox .mbox-image{border:none;padding:2px 0 2px 0.5em;text-align:center}.mw-parser-output .ambox .mbox-imageright{border:none;padding:2px 0.5em 2px 0;text-align:center}.mw-parser-output .ambox .mbox-empty-cell{border:none;padding:0;width:1px}.mw-parser-output .ambox .mbox-image-div{width:52px}@media(min-width:720px){.mw-parser-output .ambox{margin:0 10%}}@media print{body.ns-0 .mw-parser-output .ambox{display:none!important}}</style><table class="box-More_citations_needed plainlinks metadata ambox ambox-content ambox-Refimprove" role="presentation"><tbody><tr><td class="mbox-image"><div class="mbox-image-div"><span typeof="mw:File"><a href="/wiki/File:Question_book-new.svg" class="mw-file-description"><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/9/99/Question_book-new.svg/50px-Question_book-new.svg.png" decoding="async" width="50" height="39" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/9/99/Question_book-new.svg/75px-Question_book-new.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/9/99/Question_book-new.svg/100px-Question_book-new.svg.png 2x" data-file-width="512" data-file-height="399" /></a></span></div></td><td class="mbox-text"><div class="mbox-text-span">This article <b>needs additional citations for <a href="/wiki/Wikipedia:Verifiability" title="Wikipedia:Verifiability">verification</a></b>.<span class="hide-when-compact"> Please help <a href="/wiki/Special:EditPage/CDATA" title="Special:EditPage/CDATA">improve this article</a> by <a href="/wiki/Help:Referencing_for_beginners" title="Help:Referencing for beginners">adding citations to reliable sources</a>. Unsourced material may be challenged and removed.<br /><small><span class="plainlinks"><i>Find sources:</i> <a rel="nofollow" class="external text" href="https://www.google.com/search?as_eq=wikipedia&q=%22CDATA%22">"CDATA"</a> – <a rel="nofollow" class="external text" href="https://www.google.com/search?tbm=nws&q=%22CDATA%22+-wikipedia&tbs=ar:1">news</a> <b>·</b> <a rel="nofollow" class="external text" href="https://www.google.com/search?&q=%22CDATA%22&tbs=bkt:s&tbm=bks">newspapers</a> <b>·</b> <a rel="nofollow" class="external text" href="https://www.google.com/search?tbs=bks:1&q=%22CDATA%22+-wikipedia">books</a> <b>·</b> <a rel="nofollow" class="external text" href="https://scholar.google.com/scholar?q=%22CDATA%22">scholar</a> <b>·</b> <a rel="nofollow" class="external text" href="https://www.jstor.org/action/doBasicSearch?Query=%22CDATA%22&acc=on&wc=on">JSTOR</a></span></small></span> <span class="date-container"><i>(<span class="date">December 2021</span>)</i></span><span class="hide-when-compact"><i> (<small><a href="/wiki/Help:Maintenance_template_removal" title="Help:Maintenance template removal">Learn how and when to remove this message</a></small>)</i></span></div></td></tr></tbody></table> <p>The term <b>CDATA</b>, meaning <b>character data</b>, is used for distinct, but related, purposes in the <a href="/wiki/Markup_language" title="Markup language">markup languages</a> <a href="/wiki/Standard_Generalized_Markup_Language" title="Standard Generalized Markup Language">SGML</a> and <a href="/wiki/XML" title="XML">XML</a>. The term indicates that a certain portion of the document is general <i>character data</i>, rather than non-character data or character data with a more specific, limited structure. </p> <meta property="mw:PageProp/toc" /> <div class="mw-heading mw-heading2"><h2 id="CDATA_sections_in_XML">CDATA sections in XML</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=CDATA&action=edit&section=1" title="Edit section: CDATA sections in XML"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>In an XML document or external entity, a <b>CDATA section</b> is a piece of element content that is marked up to be interpreted literally, as textual data, not as marked-up content.<sup id="cite_ref-1" class="reference"><a href="#cite_note-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup> A CDATA section is merely an alternative syntax for expressing character data; there is no semantic difference between character data in a CDATA section and character data in standard syntax where, for example, "<code><</code>" and "<code>&</code>" are represented by "<code>&lt;</code>" and "<code>&amp;</code>", respectively. </p> <div class="mw-heading mw-heading3"><h3 id="Syntax_and_interpretation">Syntax and interpretation</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=CDATA&action=edit&section=2" title="Edit section: Syntax and interpretation"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>A CDATA section starts with the following sequence: </p> <div class="mw-highlight mw-highlight-lang-xml mw-content-ltr" dir="ltr"><pre><span></span><span class="err"><</span>![CDATA[ </pre></div> <p>and ends with the next occurrence of the sequence: </p> <div class="mw-highlight mw-highlight-lang-xml mw-content-ltr" dir="ltr"><pre><span></span>]]> </pre></div> <p>All characters enclosed between these two sequences are interpreted as characters, not markup or entity references. Every character is taken literally, the only exception being the <code>]]></code> sequence of characters. In: </p> <div class="mw-highlight mw-highlight-lang-xml mw-content-ltr" dir="ltr"><pre><span></span><span class="nt"><sender></span>John<span class="w"> </span>Smith<span class="nt"></sender></span> </pre></div> <p>the start and end "sender" tags are interpreted as markup. However, the code: </p> <div class="mw-highlight mw-highlight-lang-xml mw-content-ltr" dir="ltr"><pre><span></span><span class="cp"><![CDATA[<sender>John Smith</sender>]]></span> </pre></div> <p>is equivalent to: </p> <div class="mw-highlight mw-highlight-lang-xml mw-content-ltr" dir="ltr"><pre><span></span><span class="ni">&lt;</span>sender<span class="ni">&gt;</span>John<span class="w"> </span>Smith<span class="ni">&lt;</span>/sender<span class="ni">&gt;</span> </pre></div> <p>Thus, the "tags" will have exactly the same status as the "John Smith"; they will be treated as text. </p><p>Similarly, if the <a href="/wiki/Numeric_character_reference" title="Numeric character reference">numeric character reference</a> <code>&#240;</code> appears in element content, it will be interpreted as the single <a href="/wiki/Unicode" title="Unicode">Unicode</a> character 00F0 (small letter <a href="/wiki/Eth" title="Eth">eth</a>). But if the same appears in a CDATA section, it will be parsed as six characters: ampersand, hash mark, digit 2, digit 4, digit 0, semicolon. </p> <div class="mw-heading mw-heading3"><h3 id="Uses_of_CDATA_sections">Uses of CDATA sections</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=CDATA&action=edit&section=3" title="Edit section: Uses of CDATA sections"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>New authors of XML documents often misunderstand the purpose of a CDATA section, mistakenly believing that its purpose is to "protect" data from being treated as ordinary character data during processing. Some APIs for working with XML documents do offer options for independent access to CDATA sections, but such options exist above and beyond the normal requirements of XML processing systems, and still do not change the implicit meaning of the data. Character data is character data, regardless of whether it is expressed via a CDATA section or ordinary markup. CDATA sections are useful for writing XML code as text data within an XML document. For example, if one wishes to typeset a book with <a href="/wiki/Extensible_Stylesheet_Language" class="mw-redirect" title="Extensible Stylesheet Language">XSL</a> explaining the use of an XML application, the XML markup to appear in the book itself will be written in the source file in a CDATA section. </p> <div class="mw-heading mw-heading4"><h4 id="Nesting">Nesting</h4><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=CDATA&action=edit&section=4" title="Edit section: Nesting"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>A CDATA section cannot contain the string "<code>]]></code>" and therefore it is not possible for a CDATA section to contain nested CDATA sections. The preferred approach to using CDATA sections for encoding text that contains the triad "<code>]]></code>" is to use multiple CDATA sections by splitting each occurrence of the triad just before the "<code>></code>". For example, to encode "<code>]]></code>" one would write: </p> <div class="mw-highlight mw-highlight-lang-xml mw-content-ltr" dir="ltr"><pre><span></span><span class="cp"><![CDATA[]]]]><![CDATA[>]]></span> </pre></div> <p>This means that to encode "<code>]]></code>" in the middle of a CDATA section, replace all occurrences of "<code>]]></code>" with the following: </p> <div class="mw-highlight mw-highlight-lang-xml mw-content-ltr" dir="ltr"><pre><span></span>]]]]><span class="cp"><![CDATA[></span> </pre></div> <p>This effectively stops and restarts the CDATA section. </p> <div class="mw-heading mw-heading4"><h4 id="Issues_with_encoding">Issues with encoding</h4><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=CDATA&action=edit&section=5" title="Edit section: Issues with encoding"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>In text data, any Unicode character not available in the encoding declared in the <code><?xml ...?></code> header can be represented using a <code>&#nnn;</code> <a href="/wiki/Numerical_character_reference" class="mw-redirect" title="Numerical character reference">numerical character reference</a>. But the text within a CDATA section is strictly limited to the characters available in the encoding. </p><p>Because of this, using a CDATA section programmatically to quote data that could potentially contain '<code>&</code>' or '<code><</code>' characters can cause problems when the data happens to contain characters that cannot be represented in the encoding. Depending on the implementation of the encoder, these characters can get lost, can get converted to the characters of the <code>&#nnn;</code> character reference, or can cause the encoding to fail. But they will not be maintained. </p><p>Another issue is that an <a href="/wiki/XML" title="XML">XML</a> document can be transcoded from one encoding to another during transport. When the <a href="/wiki/XML" title="XML">XML</a> document is converted to a more limited character set, such as ASCII, characters that can no longer be represented are converted to <code>&#nnn;</code> character references for a lossless conversion. But within a CDATA section, these characters can not be represented at all, and have to be removed or converted to some equivalent, altering the content of the CDATA section. </p> <div class="mw-heading mw-heading2"><h2 id="Use_of_CDATA_in_program_output">Use of CDATA in program output</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=CDATA&action=edit&section=6" title="Edit section: Use of CDATA in program output"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>CDATA sections in <a href="/wiki/XHTML" title="XHTML">XHTML</a> documents are liable to be parsed differently by web browsers if they render the document as HTML, since HTML parsers do not recognise the CDATA start and end markers, nor do they recognise HTML entity references such as <code>&lt;</code> within <code><script></code> tags. This can cause rendering problems in web browsers and can lead to <a href="/wiki/Cross-site_scripting" title="Cross-site scripting">cross-site scripting</a> vulnerabilities if used to display data from untrusted sources, since the two kinds of parser will disagree on where the CDATA section ends. </p><p>Since it is useful to be able to use less-than signs (<code><</code>) and ampersands (<code>&</code>) in web page scripts, and to a lesser extent styles, without having to remember to escape them, it is common to use CDATA markers around the text of inline <code><script></code> and <code><style></code> elements in XHTML documents. But so that the document can also be parsed by HTML parsers, which do not recognise the CDATA markers, the CDATA markers are usually commented-out, as in this <a href="/wiki/JavaScript" title="JavaScript">JavaScript</a> example: </p> <div class="mw-highlight mw-highlight-lang-html mw-content-ltr" dir="ltr"><pre><span></span><span class="p"><</span><span class="nt">script</span> <span class="na">type</span><span class="o">=</span><span class="s">"text/javascript"</span><span class="p">></span> <span class="c1">//<![CDATA[</span> <span class="nb">document</span><span class="p">.</span><span class="nx">write</span><span class="p">(</span><span class="s2">"<"</span><span class="p">);</span> <span class="c1">//]]></span> <span class="p"></</span><span class="nt">script</span><span class="p">></span> </pre></div> <p>or this <a href="/wiki/Cascading_Style_Sheets" class="mw-redirect" title="Cascading Style Sheets">CSS</a> example: </p> <div class="mw-highlight mw-highlight-lang-html mw-content-ltr" dir="ltr"><pre><span></span><span class="p"><</span><span class="nt">style</span> <span class="na">type</span><span class="o">=</span><span class="s">"text/css"</span><span class="p">></span> <span class="c">/*<![CDATA[*/</span> <span class="nt">body</span><span class="w"> </span><span class="p">{</span><span class="w"> </span><span class="k">background-image</span><span class="p">:</span><span class="w"> </span><span class="nb">url</span><span class="p">(</span><span class="s2">"marble.png?width=300&height=300"</span><span class="p">)</span><span class="w"> </span><span class="p">}</span><span class="w"> </span> <span class="c">/*]]>*/</span> <span class="p"></</span><span class="nt">style</span><span class="p">></span> </pre></div> <p>This technique is only necessary when using inline scripts and stylesheets, and is language-specific. CSS stylesheets, for example, only support the second style of commenting-out (<code><span class="nowrap">/* … */</span></code>), but CSS also has less need for the <code><</code> and <code>&</code> characters than JavaScript and so less need for explicit CDATA markers. </p> <div class="mw-heading mw-heading2"><h2 id="CDATA_in_DTDs">CDATA in DTDs</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=CDATA&action=edit&section=7" title="Edit section: CDATA in DTDs"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <div class="mw-heading mw-heading3"><h3 id="CDATA-type_attribute_value">CDATA-type attribute value</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=CDATA&action=edit&section=8" title="Edit section: CDATA-type attribute value"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>In <a href="/wiki/Document_Type_Definition" class="mw-redirect" title="Document Type Definition">Document Type Definition</a> (DTD) files for SGML and XML, an attribute value may be designated as being of type CDATA: arbitrary character data. Within a CDATA-type attribute, character and entity reference markup is allowed and will be processed when the document is read. </p><p>For example, if an XML DTD contains </p> <div class="mw-highlight mw-highlight-lang-dtd mw-content-ltr" dir="ltr"><pre><span></span><span class="k"><!ATTLIST</span> <span class="nt">foo</span> <span class="na">a</span> <span class="kc">CDATA</span> <span class="kc">#IMPLIED</span><span class="k">></span> </pre></div> <p>it means that elements named foo may optionally have an attribute named "<i>a</i>" which is of type CDATA. In an XML document that is valid according to this DTD, an element like this might appear: </p> <div class="mw-highlight mw-highlight-lang-xml mw-content-ltr" dir="ltr"><pre><span></span><span class="nt"><foo</span><span class="w"> </span><span class="na">a=</span><span class="s">"1 &amp; 2 are &lt; &#51; &#x0A;"</span><span class="w"> </span><span class="nt">/></span> </pre></div> <p>and an XML parser would interpret the "<i>a</i>" attribute's value as being the character data "<i>1 & 2 are < 3</i>". </p> <div class="mw-heading mw-heading3"><h3 id="CDATA-type_entity">CDATA-type entity</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=CDATA&action=edit&section=9" title="Edit section: CDATA-type entity"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>An SGML or XML DTD may also include entity declarations in which the token CDATA is used to indicate that entity consists of character data. The character data may appear within the declaration itself or may be available externally, referenced by a <a href="/wiki/Uniform_Resource_Identifier" title="Uniform Resource Identifier">URI</a>. In either case, character reference and parameter entity reference markup is allowed in the entity, and will be processed as such when it is read. </p> <div class="mw-highlight mw-highlight-lang-xml mw-content-ltr" dir="ltr"><pre><span></span><span class="nt"><DISPLAY_NAME</span><span class="w"> </span><span class="na">Attribute=</span><span class="s">"Y"</span><span class="nt">></span><span class="cp"><![CDATA[PFTEST0__COUNTER_6__:4:199:, PFTEST0__COUNTER_7__:4:199:]]></span><span class="nt"></DISPLAY_NAME></span> <span class="nt"><SVLOBJECT><LONG</span><span class="w"> </span><span class="na">name=</span><span class="s">""</span><span class="w"> </span><span class="na">val=</span><span class="s">""</span><span class="w"> </span><span class="err">INTEGER</span><span class="w"> </span><span class="na">name=</span><span class="s">""</span><span class="w"> </span><span class="na">val=</span><span class="s">""</span><span class="w"> </span><span class="err">LONG</span><span class="w"> </span><span class="na">name=</span><span class="s">""</span><span class="w"> </span><span class="na">val=</span><span class="s">""</span><span class="nt">/></SVLOBJECT></span> </pre></div> <div class="mw-heading mw-heading2"><h2 id="See_also">See also</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=CDATA&action=edit&section=10" title="Edit section: See also"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><a href="/wiki/PCDATA" title="PCDATA">PCDATA</a></li></ul> <div class="mw-heading mw-heading2"><h2 id="References">References</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=CDATA&action=edit&section=11" title="Edit section: References"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <style data-mw-deduplicate="TemplateStyles:r1239543626">.mw-parser-output .reflist{margin-bottom:0.5em;list-style-type:decimal}@media screen{.mw-parser-output .reflist{font-size:90%}}.mw-parser-output .reflist .references{font-size:100%;margin-bottom:0;list-style-type:inherit}.mw-parser-output .reflist-columns-2{column-width:30em}.mw-parser-output .reflist-columns-3{column-width:25em}.mw-parser-output .reflist-columns{margin-top:0.3em}.mw-parser-output .reflist-columns ol{margin-top:0}.mw-parser-output .reflist-columns li{page-break-inside:avoid;break-inside:avoid-column}.mw-parser-output .reflist-upper-alpha{list-style-type:upper-alpha}.mw-parser-output .reflist-upper-roman{list-style-type:upper-roman}.mw-parser-output .reflist-lower-alpha{list-style-type:lower-alpha}.mw-parser-output .reflist-lower-greek{list-style-type:lower-greek}.mw-parser-output .reflist-lower-roman{list-style-type:lower-roman}</style><div class="reflist"> <div class="mw-references-wrap"><ol class="references"> <li id="cite_note-1"><span class="mw-cite-backlink"><b><a href="#cite_ref-1">^</a></b></span> <span class="reference-text"><a rel="nofollow" class="external text" href="https://www.w3.org/TR/REC-xml/#sec-cdata-sect">CDATA Sections</a></span> </li> </ol></div></div> <div class="mw-heading mw-heading2"><h2 id="External_links">External links</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=CDATA&action=edit&section=12" title="Edit section: External links"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><a rel="nofollow" class="external text" href="http://www.flightlab.com/~joe/sgml/cdata.html">CDATA Confusion</a></li> <li><a rel="nofollow" class="external text" href="http://www.w3.org/TR/REC-xml/#syntax">Character Data and Markup (in XML)</a></li></ul>    </div><noscript><img src="https://login.wikimedia.org/wiki/Special:CentralAutoLogin/start?type=1x1" alt="" width="1" height="1" style="border: none; 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