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   #table-example-1 tbody tr:last-child td { padding-bottom: 1.5em; }
   #table-example-1 tbody td:first-child { padding-left: 2.5em; padding-right: 0; width: 9em; }
   #table-example-1 tbody td:first-child::after { content: leader(". "); }
   #table-example-1 tbody td { padding-left: 2em; padding-right: 2em; }
   #table-example-1 tbody td:first-child + td { width: 10em; }
   #table-example-1 tbody td:first-child + td ~ td { width: 2.5em; }
   #table-example-1 tbody td:first-child + td + td + td ~ td { width: 1.25em; }

   .apple-table-examples { border: none; border-collapse: separate; border-spacing: 1.5em 0em; width: 40em; margin-left: 3em; }
   .apple-table-examples * { font-family: "Times", serif; }
   .apple-table-examples td, .apple-table-examples th { border: none; white-space: nowrap; padding-top: 0; padding-bottom: 0; }
   .apple-table-examples tbody th:first-child { border-left: none; width: 100%; }
   .apple-table-examples thead th:first-child ~ th { font-size: smaller; font-weight: bolder; border-bottom: solid 2px; text-align: center; }
   .apple-table-examples tbody th::after, .apple-table-examples tfoot th::after { content: leader(". ") }
   .apple-table-examples tbody th, .apple-table-examples tfoot th { font: inherit; text-align: left; }
   .apple-table-examples td { text-align: right; vertical-align: top; }
   .apple-table-examples.e1 tbody tr:last-child td { border-bottom: solid 1px; }
   .apple-table-examples.e1 tbody + tbody tr:last-child td { border-bottom: double 3px; }
   .apple-table-examples.e2 th[scope=row] { padding-left: 1em; }
   .apple-table-examples sup { line-height: 0; }

   .details-example img { vertical-align: top; }

   #base64-table {
     white-space: nowrap;
     font-size: 0.6em;
     column-width: 6em;
     column-count: 5;
     column-gap: 1em;
     -moz-column-width: 6em;
     -moz-column-count: 5;
     -moz-column-gap: 1em;
     -webkit-column-width: 6em;
     -webkit-column-count: 5;
     -webkit-column-gap: 1em;
   }
   #base64-table thead { display: none; }
   #base64-table * { border: none; }
   #base64-table tbody td:first-child:after { content: ':'; }
   #base64-table tbody td:last-child { text-align: right; }

   #named-character-references-table {
     white-space: nowrap;
     font-size: 0.6em;
     column-width: 30em;
     column-gap: 1em;
     -moz-column-width: 30em;
     -moz-column-gap: 1em;
     -webkit-column-width: 30em;
     -webkit-column-gap: 1em;
   }
   #named-character-references-table > table > tbody > tr > td:first-child + td,
   #named-character-references-table > table > tbody > tr > td:last-child { text-align: center; }
   #named-character-references-table > table > tbody > tr > td:last-child:hover > span { position: absolute; top: auto; left: auto; margin-left: 0.5em; line-height: 1.2; font-size: 5em; border: outset; padding: 0.25em 0.5em; background: white; width: 1.25em; height: auto; text-align: center; }
   #named-character-references-table > table > tbody > tr#entity-CounterClockwiseContourIntegral > td:first-child { font-size: 0.5em; }

   .glyph.control { color: red; }

   @font-face {
     font-family: 'Essays1743';
     src: url('http://www.whatwg.org/specs/web-apps/current-work/fonts/Essays1743.ttf');
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     font-weight: bold;
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     font-family: 'Essays1743';
     font-style: italic;
     font-weight: bold;
     src: url('http://www.whatwg.org/specs/web-apps/current-work/fonts/Essays1743-BoldItalic.ttf');
   }

  </style><style type="text/css">
   .domintro:before { display: table; margin: -1em -0.5em -0.5em auto; width: auto; content: 'This box is non-normative. Implementation requirements are given below this box.'; color: black; font-style: italic; border: solid 2px; background: white; padding: 0 0.25em; }
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  progress!</strong> For the latest updates from the HTML WG, possibly
  including important bug fixes, please look at the <a href="http://dev.w3.org/html5/spec/Overview.html">editor's draft</a> instead.
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   <p><a href="http://www.w3.org/"><img alt="W3C" height="48" src="http://www.w3.org/Icons/w3c_home" width="72"></a></p>

   <h1>HTML5</h1>
   </div><div>
   <a href="commands.html" class="prev">4.11.5 Commands</a> &#8211;
   <a href="spec.html#contents">Table of contents</a> &#8211;
   <a href="browsers.html" class="next">5 Loading Web pages</a>
  <ol class="toc"><li><ol><li><a href="links.html#links"><span class="secno">4.12 </span>Links</a>
    <ol><li><a href="links.html#introduction-3"><span class="secno">4.12.1 </span>Introduction</a></li><li><a href="links.html#links-created-by-a-and-area-elements"><span class="secno">4.12.2 </span>Links created by <code>a</code> and <code>area</code> elements</a></li><li><a href="links.html#following-hyperlinks"><span class="secno">4.12.3 </span>Following hyperlinks</a></li><li><a href="links.html#linkTypes"><span class="secno">4.12.4 </span>Link types</a>
      <ol><li><a href="links.html#rel-alternate"><span class="secno">4.12.4.1 </span>Link type "<code>alternate</code>"</a></li><li><a href="links.html#link-type-author"><span class="secno">4.12.4.2 </span>Link type "<code>author</code>"</a></li><li><a href="links.html#link-type-bookmark"><span class="secno">4.12.4.3 </span>Link type "<code>bookmark</code>"</a></li><li><a href="links.html#link-type-external"><span class="secno">4.12.4.4 </span>Link type "<code>external</code>"</a></li><li><a href="links.html#link-type-help"><span class="secno">4.12.4.5 </span>Link type "<code>help</code>"</a></li><li><a href="links.html#rel-icon"><span class="secno">4.12.4.6 </span>Link type "<code>icon</code>"</a></li><li><a href="links.html#link-type-license"><span class="secno">4.12.4.7 </span>Link type "<code>license</code>"</a></li><li><a href="links.html#link-type-nofollow"><span class="secno">4.12.4.8 </span>Link type "<code>nofollow</code>"</a></li><li><a href="links.html#link-type-noreferrer"><span class="secno">4.12.4.9 </span>Link type "<code>noreferrer</code>"</a></li><li><a href="links.html#link-type-pingback"><span class="secno">4.12.4.10 </span>Link type "<code>pingback</code>"</a></li><li><a href="links.html#link-type-prefetch"><span class="secno">4.12.4.11 </span>Link type "<code>prefetch</code>"</a></li><li><a href="links.html#link-type-search"><span class="secno">4.12.4.12 </span>Link type "<code>search</code>"</a></li><li><a href="links.html#link-type-sidebar"><span class="secno">4.12.4.13 </span>Link type "<code>sidebar</code>"</a></li><li><a href="links.html#link-type-stylesheet"><span class="secno">4.12.4.14 </span>Link type "<code>stylesheet</code>"</a></li><li><a href="links.html#link-type-tag"><span class="secno">4.12.4.15 </span>Link type "<code>tag</code>"</a></li><li><a href="links.html#sequential-link-types"><span class="secno">4.12.4.16 </span>Sequential link types</a>
        <ol><li><a href="links.html#link-type-next"><span class="secno">4.12.4.16.1 </span>Link type "<code>next</code>"</a></li><li><a href="links.html#link-type-prev"><span class="secno">4.12.4.16.2 </span>Link type "<code>prev</code>"</a></li></ol></li><li><a href="links.html#other-link-types"><span class="secno">4.12.4.17 </span>Other link types</a></li></ol></li></ol></li><li><a href="links.html#common-idioms-without-dedicated-elements"><span class="secno">4.13 </span>Common idioms without dedicated elements</a>
    <ol><li><a href="links.html#the-main-part-of-the-content"><span class="secno">4.13.1 </span>The main part of the content</a></li><li><a href="links.html#rel-up"><span class="secno">4.13.2 </span>Bread crumb navigation</a></li><li><a href="links.html#tag-clouds"><span class="secno">4.13.3 </span>Tag clouds</a></li><li><a href="links.html#conversations"><span class="secno">4.13.4 </span>Conversations</a></li><li><a href="links.html#footnotes"><span class="secno">4.13.5 </span>Footnotes</a></li></ol></li><li><a href="links.html#matching-html-elements-using-selectors"><span class="secno">4.14 </span>Matching HTML elements using selectors</a>
    <ol><li><a href="links.html#selectors"><span class="secno">4.14.1 </span>Case-sensitivity</a></li><li><a href="links.html#pseudo-classes"><span class="secno">4.14.2 </span>Pseudo-classes</a></li></ol></li></ol></li></ol></div>

  <h3 id="links"><span class="secno">4.12 </span>Links</h3><h4 id="introduction-3"><span class="secno">4.12.1 </span>Introduction</h4><p>Links are a conceptual construct, created by <code><a href="text-level-semantics.html#the-a-element">a</a></code>,
  <code><a href="the-map-element.html#the-area-element">area</a></code>, and <code><a href="semantics.html#the-link-element">link</a></code> elements, that <a href="rendering.html#represents" title="represents">represent</a> a connection between two
  resources, one of which is the current <code><a href="infrastructure.html#document">Document</a></code>. There
  are two kinds of links in HTML:</p><dl><dt><dfn id="external-resource-link" title="external resource link">Links to external
   resources</dfn></dt>

   <dd><p>These are links to resources that are to be used to augment
   the current document, generally automatically processed by the user
   agent.</p></dd>

   <dt><dfn id="hyperlink" title="hyperlink">Hyperlinks</dfn></dt>

   <dd><p>These are links to other resources that are generally
   exposed to the user by the user agent so that the user can cause
   the user agent to <a href="history.html#navigate">navigate</a> to those resources, e.g. to
   visit them in a browser or download them.</p></dd>

  </dl><p>For <code><a href="semantics.html#the-link-element">link</a></code> elements with an <code title="attr-link-href"><a href="semantics.html#attr-link-href">href</a></code> attribute and a <code title="attr-link-rel"><a href="semantics.html#attr-link-rel">rel</a></code> attribute, links must be created
  for the keywords of the <code title="attr-link-rel"><a href="semantics.html#attr-link-rel">rel</a></code>
  attribute, as defined for those keywords in the <a href="#linkTypes">link types</a> section.</p><p>Similarly, for <code><a href="text-level-semantics.html#the-a-element">a</a></code> and <code><a href="the-map-element.html#the-area-element">area</a></code> elements with
  an <code title="attr-hyperlink-href"><a href="#attr-hyperlink-href">href</a></code> attribute and a
  <code title="attr-hyperlink-rel"><a href="#attr-hyperlink-rel">rel</a></code> attribute, links must be
  created for the keywords of the <code title="attr-hyperlink-rel"><a href="#attr-hyperlink-rel">rel</a></code> attribute as defined for those
  keywords in the <a href="#linkTypes">link types</a> section. Unlike
  <code><a href="semantics.html#the-link-element">link</a></code> elements, however, <code><a href="text-level-semantics.html#the-a-element">a</a></code> and
  <code><a href="the-map-element.html#the-area-element">area</a></code> element with an <code title="attr-hyperlink-href"><a href="#attr-hyperlink-href">href</a></code> attribute that either do not
  have a <code title="attr-hyperlink-rel"><a href="#attr-hyperlink-rel">rel</a></code> attribute, or
  whose <code title="attr-hyperlink-rel"><a href="#attr-hyperlink-rel">rel</a></code> attribute has no
  keywords that are defined as specifying <a href="#hyperlink" title="hyperlink">hyperlinks</a>, must also create a
  <a href="#hyperlink">hyperlink</a>. This implied hyperlink has no special
  meaning (it has no <a href="#linkTypes">link type</a>) beyond
  linking the element's document to the resource given by the
  element's <code title="attr-hyperlink-href"><a href="#attr-hyperlink-href">href</a></code>
  attribute.</p><p>A <a href="#hyperlink">hyperlink</a> can have one or more <dfn id="hyperlink-annotation" title="hyperlink annotation">hyperlink annotations</dfn> that modify
  the processing semantics of that hyperlink.</p><h4 id="links-created-by-a-and-area-elements"><span class="secno">4.12.2 </span>Links created by <code><a href="text-level-semantics.html#the-a-element">a</a></code> and <code><a href="the-map-element.html#the-area-element">area</a></code> elements</h4><p>The <dfn id="attr-hyperlink-href" title="attr-hyperlink-href"><code>href</code></dfn>
  attribute on <code><a href="text-level-semantics.html#the-a-element">a</a></code> and <code><a href="the-map-element.html#the-area-element">area</a></code> elements must have
  a value that is a <a href="urls.html#valid-url-potentially-surrounded-by-spaces">valid URL potentially surrounded by
  spaces</a>.</p><p class="note">The <code title="attr-hyperlink-href"><a href="#attr-hyperlink-href">href</a></code>
  attribute on <code><a href="text-level-semantics.html#the-a-element">a</a></code> and <code><a href="the-map-element.html#the-area-element">area</a></code> elements is not
  required; when those elements do not have <code title="attr-hyperlink-href"><a href="#attr-hyperlink-href">href</a></code> attributes they do not
  create hyperlinks.</p><p>The <dfn id="attr-hyperlink-target" title="attr-hyperlink-target"><code>target</code></dfn>
  attribute, if present, must be a <a href="browsers.html#valid-browsing-context-name-or-keyword">valid browsing context name
  or keyword</a>. It gives the name of the <a href="browsers.html#browsing-context">browsing
  context</a> that will be used. <span class="impl">User agents use
  this name when <a href="#following-hyperlinks">following hyperlinks</a>.</span></p><p>The <dfn id="attr-hyperlink-rel" title="attr-hyperlink-rel"><code>rel</code></dfn>
  attribute on <code><a href="text-level-semantics.html#the-a-element">a</a></code> and <code><a href="the-map-element.html#the-area-element">area</a></code> elements controls
  what kinds of links the elements create. The attribue's value must
  be a <a href="common-microsyntaxes.html#set-of-space-separated-tokens">set of space-separated tokens</a>. The <a href="#linkTypes">allowed keywords and their meanings</a> are
  defined below.</p><p>The <code title="attr-hyperlink-rel"><a href="#attr-hyperlink-rel">rel</a></code> attribute has
  no default value. If the attribute is omitted or if none of the
  values in the attribute are recognized by the user agent, then the
  document has no particular relationship with the destination
  resource other than there being a hyperlink between the two.</p><p>The <dfn id="attr-hyperlink-media" title="attr-hyperlink-media"><code>media</code></dfn>
  attribute describes for which media the target document was
  designed. It is purely advisory. The value must be a <a href="common-microsyntaxes.html#valid-media-query">valid
  media query</a>. The default, if the <code title="attr-hyperlink-media"><a href="#attr-hyperlink-media">media</a></code> attribute is omitted, is
  "<code title="">all</code>".</p><p>The <dfn id="attr-hyperlink-hreflang" title="attr-hyperlink-hreflang"><code>hreflang</code></dfn>
  attribute on <code><a href="text-level-semantics.html#the-a-element">a</a></code> and <code><a href="the-map-element.html#the-area-element">area</a></code> elements that
  create <a href="#hyperlink" title="hyperlink">hyperlinks</a>, if present, gives
  the language of the linked resource. It is purely advisory. The
  value must be a valid BCP 47 language tag. <a href="references.html#refsBCP47">[BCP47]</a> <span class="impl">User agents must
  not consider this attribute authoritative &#8212; upon fetching the
  resource, user agents must use only language information associated
  with the resource to determine its language, not metadata included
  in the link to the resource.</span></p><p>The <dfn id="attr-hyperlink-type" title="attr-hyperlink-type"><code>type</code></dfn>
  attribute, if present, gives the <a href="infrastructure.html#mime-type">MIME type</a> of the
  linked resource. It is purely advisory. The value must be a
  <a href="infrastructure.html#valid-mime-type">valid MIME type</a>. <span class="impl">User agents must
  not consider the <code title="attr-hyperlink-type"><a href="#attr-hyperlink-type">type</a></code>
  attribute authoritative &#8212; upon fetching the resource, user
  agents must not use metadata included in the link to the resource to
  determine its type.</span></p><div class="impl">

  <h4 id="following-hyperlinks"><span class="secno">4.12.3 </span><dfn>Following hyperlinks</dfn></h4>

  <p>When a user <em>follows a hyperlink</em> created by an element,
  the user agent must <a href="urls.html#resolve-a-url" title="resolve a url">resolve</a> the
  <a href="urls.html#url">URL</a> given by the <code title="attr-hyperlink-href"><a href="#attr-hyperlink-href">href</a></code> attribute of that element,
  relative to that element, and if that is successful, must
  <a href="history.html#navigate">navigate</a> a <a href="browsers.html#browsing-context">browsing
  context</a> to the resulting <a href="urls.html#absolute-url">absolute URL</a>. In the
  case of server-side image maps, that <a href="urls.html#absolute-url">absolute URL</a> must
  have its <var><a href="text-level-semantics.html#hyperlink-suffix">hyperlink suffix</a></var> appended to it before the
  navigation is started.</p>

  <p>If <a href="urls.html#resolve-a-url" title="resolve a url">resolving</a> the
  <a href="urls.html#url">URL</a> fails, the user agent may report the error to the
  user in a user-agent-specific manner, may
  <a href="history.html#navigate">navigate</a> to an error page to
  report the error, or may ignore the error and do nothing.</p>

  <p>If the user indicated a specific <a href="browsers.html#browsing-context">browsing context</a>
  when following the hyperlink, or if the user agent is configured to
  follow hyperlinks by navigating a particular browsing context, then
  that must be the <a href="browsers.html#browsing-context">browsing context</a> that is
  navigated.</p>

  <p>Otherwise, if the element is an <code><a href="text-level-semantics.html#the-a-element">a</a></code> or
  <code><a href="the-map-element.html#the-area-element">area</a></code> element that has a <code title="attr-hyperlink-target"><a href="#attr-hyperlink-target">target</a></code> attribute, then the
  <a href="browsers.html#browsing-context">browsing context</a> that is navigated must be chosen by
  applying <a href="browsers.html#the-rules-for-choosing-a-browsing-context-given-a-browsing-context-name">the rules for choosing a browsing context given a
  browsing context name</a>, using the value of the <code title="attr-hyperlink-target"><a href="#attr-hyperlink-target">target</a></code> attribute as the
  browsing context name. If these rules result in the creation of a
  new <a href="browsers.html#browsing-context">browsing context</a>, it must be navigated with
  <a href="history.html#replacement-enabled">replacement enabled</a>.</p>

  <p>Otherwise, if the hyperlink is a <a href="#rel-sidebar-hyperlink" title="rel-sidebar-hyperlink">sidebar hyperlink</a> and the user
  agent implements a feature that can be considered a secondary
  browsing context, such a secondary browsing context may be selected
  as the browsing context to be navigated.</p>

  <p>Otherwise, if the element is an <code><a href="text-level-semantics.html#the-a-element">a</a></code> or
  <code><a href="the-map-element.html#the-area-element">area</a></code> element with no <code title="attr-hyperlink-target"><a href="#attr-hyperlink-target">target</a></code> attribute, but the
  <code><a href="infrastructure.html#document">Document</a></code> contains a <code><a href="semantics.html#the-base-element">base</a></code> element with a
  <code title="attr-base-target"><a href="semantics.html#attr-base-target">target</a></code> attribute, then the
  browsing context that is navigated must be chosen by applying
  <a href="browsers.html#the-rules-for-choosing-a-browsing-context-given-a-browsing-context-name">the rules for choosing a browsing context given a browsing
  context name</a>, using the value of the <code title="attr-base-target"><a href="semantics.html#attr-base-target">target</a></code> attribute of the first such
  <code><a href="semantics.html#the-base-element">base</a></code> element as the browsing context name. If these
  rules result in the creation of a new <a href="browsers.html#browsing-context">browsing context</a>,
  it must be navigated with <a href="history.html#replacement-enabled">replacement enabled</a>.</p>
  

  <p>Otherwise, the browsing context that must be navigated is the
  same browsing context as the one which the element itself is in.</p>

  <p>The navigation must be done with the <a href="browsers.html#browsing-context">browsing
  context</a> that contains the <code><a href="infrastructure.html#document">Document</a></code> object with
  which the element in question is associated as the <a href="history.html#source-browsing-context">source
  browsing context</a>.</p>

  </div><h4 id="linkTypes"><span class="secno">4.12.4 </span>Link types</h4><p>The following table summarizes the link types that are defined by
  this specification. This table is non-normative; the actual
  definitions for the link types are given in the next few
  sections.</p><p>In this section, the term <i>referenced document</i> refers to
  the resource identified by the element representing the link, and
  the term <i>current document</i> refers to the resource within
  which the element representing the link finds itself.</p><div class="impl">

  <p>To determine which link types apply to a <code><a href="semantics.html#the-link-element">link</a></code>,
  <code><a href="text-level-semantics.html#the-a-element">a</a></code>, or <code><a href="the-map-element.html#the-area-element">area</a></code> element, the element's <code title="">rel</code> attribute must be <a href="common-microsyntaxes.html#split-a-string-on-spaces" title="split a string on
  spaces">split on spaces</a>. The resulting tokens are the link
  types that apply to that element.</p>

  </div><p>Except where otherwise specified, a keyword must not be specified
  more than once per <code title="attr-hyperlink-rel"><a href="#attr-hyperlink-rel">rel</a></code>
  attribute.</p><p>The link types that contain no U+003A COLON characters (:),
  including all those defined in this specification, are <a href="infrastructure.html#ascii-case-insensitive">ASCII
  case-insensitive</a> values<span class="impl">, and must be
  compared as such</span>.</p><p class="example">Thus, <code title="">rel="next"</code> is the
  same as <code title="">rel="NEXT"</code>.</p><table><thead><tr><th rowspan="2">Link type</th>
     <th colspan="2">Effect on...</th>
     <th rowspan="2">Brief description</th>
    </tr><tr><th><code><a href="semantics.html#the-link-element">link</a></code></th>
     <th><code><a href="text-level-semantics.html#the-a-element">a</a></code> and <code><a href="the-map-element.html#the-area-element">area</a></code></th>
    </tr></thead><tbody><tr><td><code title="rel-alternate"><a href="#rel-alternate">alternate</a></code></td> 
     <td><a href="#hyperlink">Hyperlink</a></td>
     <td><a href="#hyperlink">Hyperlink</a></td>
     <td>Gives alternate representations of the current document.</td>
    </tr><tr><td><code title="rel-author"><a href="#link-type-author">author</a></code></td>
     <td><a href="#hyperlink">Hyperlink</a></td>
     <td><a href="#hyperlink">Hyperlink</a></td>
     <td>Gives a link to the current document's author.</td>
    </tr><tr><td><code title="rel-bookmark"><a href="#link-type-bookmark">bookmark</a></code></td> 
     <td><em>not allowed</em></td>
     <td><a href="#hyperlink">Hyperlink</a></td>
     <td>Gives the permalink for the nearest ancestor section.</td>
    </tr><tr><td><code title="rel-external"><a href="#link-type-external">external</a></code></td> 
     <td><em>not allowed</em></td>
     <td><a href="#hyperlink">Hyperlink</a></td>
     <td>Indicates that the referenced document is not part of the same site as the current document.</td>
    </tr><tr><td><code title="rel-help"><a href="#link-type-help">help</a></code></td>
     <td><a href="#hyperlink">Hyperlink</a></td>
     <td><a href="#hyperlink">Hyperlink</a></td>
     <td>Provides a link to context-sensitive help.</td>
    </tr><tr><td><code title="rel-icon"><a href="#rel-icon">icon</a></code></td> 
     <td><a href="#external-resource-link" title="external resource link">External Resource</a></td>
     <td><em>not allowed</em></td>
     <td>Imports an icon to represent the current document.</td>
    </tr><tr><td><code title="rel-license"><a href="#link-type-license">license</a></code></td> 
     <td><a href="#hyperlink">Hyperlink</a></td>
     <td><a href="#hyperlink">Hyperlink</a></td>
     <td>Indicates that the main content of the current document is covered by the copyright license described by the referenced document.</td>
    </tr><tr><td><code title="rel-next"><a href="#link-type-next">next</a></code></td>
     <td><a href="#hyperlink">Hyperlink</a></td>
     <td><a href="#hyperlink">Hyperlink</a></td>
     <td>Indicates that the current document is a part of a series, and that the next document in the series is the referenced document.</td>
    </tr><tr><td><code title="rel-nofollow"><a href="#link-type-nofollow">nofollow</a></code></td> 
     <td><em>not allowed</em></td>
     <td><a href="#hyperlink-annotation" title="hyperlink annotation">Annotation</a></td>
     <td>Indicates that the current document's original author or publisher does not endorse the referenced document.</td>
    </tr><tr><td><code title="rel-noreferrer"><a href="#link-type-noreferrer">noreferrer</a></code></td>
     <td><em>not allowed</em></td>
     <td><a href="#hyperlink-annotation" title="hyperlink annotation">Annotation</a></td>
     <td>Requires that the user agent not send an HTTP <code title="http-referer">Referer</code> (sic) header if the user follows the hyperlink.</td>
    </tr><tr><td><code title="rel-pingback"><a href="#link-type-pingback">pingback</a></code></td>
     <td><a href="#external-resource-link" title="external resource link">External Resource</a></td>
     <td><em>not allowed</em></td>
     <td>Gives the address of the pingback server that handles pingbacks to the current document.</td>
    </tr><tr><td><code title="rel-prefetch"><a href="#link-type-prefetch">prefetch</a></code></td>
     <td><a href="#external-resource-link" title="external resource link">External Resource</a></td>
     <td><a href="#external-resource-link" title="external resource link">External Resource</a></td>
     <td>Specifies that the target resource should be preemptively cached.</td>
    </tr><tr><td><code title="rel-prev"><a href="#link-type-prev">prev</a></code></td> 
     <td><a href="#hyperlink">Hyperlink</a></td>
     <td><a href="#hyperlink">Hyperlink</a></td>
     <td>Indicates that the current document is a part of a series, and that the previous document in the series is the referenced document.</td>
    </tr><tr><td><code title="rel-search"><a href="#link-type-search">search</a></code></td> 
     <td><a href="#hyperlink">Hyperlink</a></td>
     <td><a href="#hyperlink">Hyperlink</a></td>
     <td>Gives a link to a resource that can be used to search through the current document and its related pages.</td>
    </tr><tr><td><code title="rel-sidebar"><a href="#link-type-sidebar">sidebar</a></code></td> 
     <td><a href="#hyperlink">Hyperlink</a></td>
     <td><a href="#hyperlink">Hyperlink</a></td>
     <td>Specifies that the referenced document, if retrieved, is intended to be shown in the browser's sidebar (if it has one).</td>
    </tr><tr><td><code title="rel-stylesheet"><a href="#link-type-stylesheet">stylesheet</a></code></td> 
     <td><a href="#external-resource-link" title="external resource link">External Resource</a></td>
     <td><em>not allowed</em></td>
     <td>Imports a stylesheet.</td>
    </tr><tr><td><code title="rel-tag"><a href="#link-type-tag">tag</a></code></td> 
     <td><a href="#hyperlink">Hyperlink</a></td>
     <td><a href="#hyperlink">Hyperlink</a></td>
     <td>Gives a tag (identified by the given address) that applies to the current document.</td>
    </tr></tbody></table><div class="impl">

  <p>Some of the types described below list synonyms for these
  values. These are to be handled as
  specified by user agents, but must not be used in
  documents.</p>

  </div><h5 id="rel-alternate"><span class="secno">4.12.4.1 </span>Link type "<dfn title="rel-alternate"><code>alternate</code></dfn>"</h5><p>The <code title="rel-alternate"><a href="#rel-alternate">alternate</a></code> keyword may be
  used with <code><a href="semantics.html#the-link-element">link</a></code>, <code><a href="text-level-semantics.html#the-a-element">a</a></code>, and <code><a href="the-map-element.html#the-area-element">area</a></code>
  elements.</p><p>The meaning of this keyword depends on the values of the other
  attributes.</p><dl class="switch"><dt>If the element is a <code><a href="semantics.html#the-link-element">link</a></code> element and the <code title="attr-link-rel"><a href="semantics.html#attr-link-rel">rel</a></code> attribute also contains the
   keyword <code title="rel-stylesheet"><a href="#link-type-stylesheet">stylesheet</a></code></dt>

   <dd>

    <p>The <code title="rel-alternate"><a href="#rel-alternate">alternate</a></code> keyword
    modifies the meaning of the <code title="rel-stylesheet"><a href="#link-type-stylesheet">stylesheet</a></code> keyword in the way
    described for that keyword. The <code title="rel-alternate"><a href="#rel-alternate">alternate</a></code> keyword does not create a
    link of its own.</p>

   </dd>


   <dt>The <code title="rel-alternate"><a href="#rel-alternate">alternate</a></code> keyword is
   used with the <code title="attr-hyperlink-type"><a href="#attr-hyperlink-type">type</a></code>
   attribute set to the value <code title="">application/rss+xml</code> or the value <code title="">application/atom+xml</code></dt>

   <dd>

    <p>The keyword creates a <a href="#hyperlink">hyperlink</a> referencing a
    syndication feed (though not necessarily syndicating exactly the
    same content as the current page).</p>

    <div class="impl">

    <p>The first <code><a href="semantics.html#the-link-element">link</a></code>, <code><a href="text-level-semantics.html#the-a-element">a</a></code>, or <code><a href="the-map-element.html#the-area-element">area</a></code>
    element in the document (in tree order) with the <code title="rel-alternate"><a href="#rel-alternate">alternate</a></code> keyword used with the <code title="attr-hyperlink-type"><a href="#attr-hyperlink-type">type</a></code> attribute set to the value
    <code title="">application/rss+xml</code> or the value <code title="">application/atom+xml</code> must be treated as the default
    syndication feed for the purposes of feed autodiscovery.</p>

    <div class="example">
     <p>The following <code><a href="semantics.html#the-link-element">link</a></code> element gives the syndication
     feed for the current page:</p>
     <pre>&lt;link rel="alternate" type="application/atom+xml" href="data.xml"&gt;</pre>
     <p>The following extract offers various different syndication
     feeds:</p>
     <pre>&lt;p&gt;You can access the planets database using Atom feeds:&lt;/p&gt;
&lt;ul&gt;
 &lt;li&gt;&lt;a href="recently-visited-planets.xml" rel="alternate" type="application/atom+xml"&gt;Recently Visited Planets&lt;/a&gt;&lt;/li&gt;
 &lt;li&gt;&lt;a href="known-bad-planets.xml" rel="alternate" type="application/atom+xml"&gt;Known Bad Planets&lt;/a&gt;&lt;/li&gt;
 &lt;li&gt;&lt;a href="unexplored-planets.xml" rel="alternate" type="application/atom+xml"&gt;Unexplored Planets&lt;/a&gt;&lt;/li&gt;
&lt;/ul&gt;</pre>
    </div>

    </div>

   </dd>


   <dt>Otherwise</dt>

   <dd>

    <p>The keyword creates a <a href="#hyperlink">hyperlink</a> referencing an
    alternate representation of the current document.</p>

    <p>The nature of the referenced document is given by the <code title="attr-hyperlink-media"><a href="#attr-hyperlink-media">media</a></code>, <code title="attr-hyperlink-hreflang"><a href="#attr-hyperlink-hreflang">hreflang</a></code>, and <code title="attr-hyperlink-type"><a href="#attr-hyperlink-type">type</a></code> attributes.</p>

    <p>If the <code title="rel-alternate"><a href="#rel-alternate">alternate</a></code> keyword is
    used with the <code title="attr-hyperlink-media"><a href="#attr-hyperlink-media">media</a></code>
    attribute, it indicates that the referenced document is intended for
    use with the media specified.</p>

    <p>If the <code title="rel-alternate"><a href="#rel-alternate">alternate</a></code> keyword is
    used with the <code title="attr-hyperlink-hreflang"><a href="#attr-hyperlink-hreflang">hreflang</a></code>
    attribute, and that attribute's value differs from the <a href="infrastructure.html#root-element">root
    element</a>'s <a href="elements.html#language">language</a>, it indicates that the
    referenced document is a translation.</p>

    <p>If the <code title="rel-alternate"><a href="#rel-alternate">alternate</a></code> keyword is
    used with the <code title="attr-hyperlink-type"><a href="#attr-hyperlink-type">type</a></code>
    attribute, it indicates that the referenced document is a
    reformulation of the current document in the specified format.</p>

    <p>The <code title="attr-hyperlink-media"><a href="#attr-hyperlink-media">media</a></code>, <code title="attr-hyperlink-hreflang"><a href="#attr-hyperlink-hreflang">hreflang</a></code>, and <code title="attr-hyperlink-type"><a href="#attr-hyperlink-type">type</a></code> attributes can be combined
    when specified with the <code title="rel-alternate"><a href="#rel-alternate">alternate</a></code>
    keyword.</p>

    <div class="example">

     <p>For example, the following link is a French translation that
     uses the PDF format:</p>

     <pre>&lt;link rel=alternate type=application/pdf hreflang=fr href=manual-fr&gt;</pre>

    </div>

    <p>This relationship is transitive &#8212; that is, if a document
    links to two other documents with the link type "<code title="rel-alternate"><a href="#rel-alternate">alternate</a></code>", then, in addition to
    implying that those documents are alternative representations of
    the first document, it is also implying that those two documents
    are alternative representations of each other.</p>

   </dd>

  </dl><h5 id="link-type-author"><span class="secno">4.12.4.2 </span>Link type "<dfn title="rel-author"><code>author</code></dfn>"</h5><p>The <code title="rel-author"><a href="#link-type-author">author</a></code> keyword may be
  used with <code><a href="semantics.html#the-link-element">link</a></code>, <code><a href="text-level-semantics.html#the-a-element">a</a></code>, and <code><a href="the-map-element.html#the-area-element">area</a></code>
  elements. This keyword creates a <a href="#hyperlink">hyperlink</a>.</p><p>For <code><a href="text-level-semantics.html#the-a-element">a</a></code> and <code><a href="the-map-element.html#the-area-element">area</a></code> elements, the <code title="rel-author"><a href="#link-type-author">author</a></code> keyword indicates that the
  referenced document provides further information about the author of
  the nearest <code><a href="sections.html#the-article-element">article</a></code> element ancestor of the element
  defining the hyperlink, if there is one, or of the page as a whole,
  otherwise.</p><p>For <code><a href="semantics.html#the-link-element">link</a></code> elements, the <code title="rel-author"><a href="#link-type-author">author</a></code> keyword indicates that the
  referenced document provides further information about the author
  for the page as a whole.</p><p class="note">The "referenced document" can be, and often is, a
  <code title="">mailto:</code> URL giving the e-mail address of the
  author. <a href="references.html#refsMAILTO">[MAILTO]</a></p><div class="impl">

  <p><strong>Synonyms</strong>: For historical reasons, user agents
  must also treat <code><a href="semantics.html#the-link-element">link</a></code>, <code><a href="text-level-semantics.html#the-a-element">a</a></code>, and
  <code><a href="the-map-element.html#the-area-element">area</a></code> elements that have a <code title="">rev</code>
  attribute with the value "<code>made</code>" as having the <code title="rel-author"><a href="#link-type-author">author</a></code> keyword specified as a link
  relationship.</p>

  </div><h5 id="link-type-bookmark"><span class="secno">4.12.4.3 </span>Link type "<dfn title="rel-bookmark"><code>bookmark</code></dfn>"</h5><p>The <code title="rel-bookmark"><a href="#link-type-bookmark">bookmark</a></code> keyword may be
  used with <code><a href="text-level-semantics.html#the-a-element">a</a></code> and <code><a href="the-map-element.html#the-area-element">area</a></code> elements. This
  keyword creates a <a href="#hyperlink">hyperlink</a>.</p><p>The <code title="rel-bookmark"><a href="#link-type-bookmark">bookmark</a></code> keyword gives a
  permalink for the nearest ancestor <code><a href="sections.html#the-article-element">article</a></code> element of
  the linking element in question, or of <a href="sections.html#associatedSection">the section the linking element is most
  closely associated with</a>, if there are no ancestor
  <code><a href="sections.html#the-article-element">article</a></code> elements.</p><div class="example">
   <p>The following snippet has three permalinks. A user agent could
   determine which permalink applies to which part of the spec by
   looking at where the permalinks are given.</p>
   <pre> ...
 &lt;body&gt;
  &lt;h1&gt;Example of permalinks&lt;/h1&gt;
  &lt;div id="a"&gt;
   &lt;h2&gt;First example&lt;/h2&gt;
   &lt;p&gt;&lt;a href="a.html" rel="bookmark"&gt;This&lt;/a&gt; permalink applies to
   only the content from the first H2 to the second H2. The DIV isn't
   exactly that section, but it roughly corresponds to it.&lt;/p&gt;
  &lt;/div&gt;
  &lt;h2&gt;Second example&lt;/h2&gt;
  &lt;article id="b"&gt;
   &lt;p&gt;&lt;a href="b.html" rel="bookmark"&gt;This&lt;/a&gt; permalink applies to
   the outer ARTICLE element (which could be, e.g., a blog post).&lt;/p&gt;
   &lt;article id="c"&gt;
    &lt;p&gt;&lt;a href="c.html" rel="bookmark"&gt;This&lt;/a&gt; permalink applies to
    the inner ARTICLE element (which could be, e.g., a blog comment).&lt;/p&gt;
   &lt;/article&gt;
  &lt;/article&gt;
 &lt;/body&gt;
 ...</pre>
  </div><h5 id="link-type-external"><span class="secno">4.12.4.4 </span>Link type "<dfn title="rel-external"><code>external</code></dfn>"</h5><p>The <code title="rel-external"><a href="#link-type-external">external</a></code> keyword may be
  used with <code><a href="text-level-semantics.html#the-a-element">a</a></code> and <code><a href="the-map-element.html#the-area-element">area</a></code> elements. This
  keyword creates a <a href="#hyperlink">hyperlink</a>.</p><p>The <code title="rel-external"><a href="#link-type-external">external</a></code> keyword indicates
  that the link is leading to a document that is not part of the site
  that the current document forms a part of.</p><h5 id="link-type-help"><span class="secno">4.12.4.5 </span>Link type "<dfn title="rel-help"><code>help</code></dfn>"</h5><p>The <code title="rel-help"><a href="#link-type-help">help</a></code> keyword may be used with
  <code><a href="semantics.html#the-link-element">link</a></code>, <code><a href="text-level-semantics.html#the-a-element">a</a></code>, and <code><a href="the-map-element.html#the-area-element">area</a></code>
  elements. This keyword creates a <a href="#hyperlink">hyperlink</a>.</p><p>For <code><a href="text-level-semantics.html#the-a-element">a</a></code> and <code><a href="the-map-element.html#the-area-element">area</a></code> elements, the <code title="rel-help"><a href="#link-type-help">help</a></code> keyword indicates that the referenced
  document provides further help information for the parent of the
  element defining the hyperlink, and its children.</p><div class="example">

   <p>In the following example, the form control has associated
   context-sensitive help. The user agent could use this information,
   for example, displaying the referenced document if the user presses
   the "Help" or "F1" key.</p>

   <pre> &lt;p&gt;&lt;label&gt; Topic: &lt;input name=topic&gt; &lt;a href="help/topic.html" rel="help"&gt;(Help)&lt;/a&gt;&lt;/label&gt;&lt;/p&gt;</pre>

  </div><p>For <code><a href="semantics.html#the-link-element">link</a></code> elements, the <code title="rel-help"><a href="#link-type-help">help</a></code> keyword indicates that the referenced
  document provides help for the page as a whole.</p><h5 id="rel-icon"><span class="secno">4.12.4.6 </span>Link type "<dfn title="rel-icon"><code>icon</code></dfn>"</h5><p>The <code title="rel-icon"><a href="#rel-icon">icon</a></code> keyword may be used with
  <code><a href="semantics.html#the-link-element">link</a></code> elements. This keyword creates an <a href="#external-resource-link" title="external resource link">external resource link</a>.</p><div class="impl">

  <p>The specified resource is an icon representing the page or site,
  and should be used by the user agent when representing the page in
  the user interface.</p>

  </div><p>Icons could be auditory icons, visual icons, or other kinds of
  icons. <span class="impl">If multiple icons are provided, the user
  agent must select the most appropriate icon according to the <code title="attr-link-type"><a href="semantics.html#attr-link-type">type</a></code>, <code title="attr-link-media"><a href="semantics.html#attr-link-media">media</a></code>, and <code title="attr-link-sizes"><a href="#attr-link-sizes">sizes</a></code> attributes. If there are
  multiple equally appropriate icons, user agents must use the last
  one declared in <a href="infrastructure.html#tree-order">tree order</a>. If the user agent tries to
  use an icon but that icon is determined, upon closer examination, to
  in fact be inappropriate (e.g. because it uses an unsupported
  format), then the user agent must try the next-most-appropriate icon
  as determined by the attributes.</span></p><div class="impl">

  <p>There is no default type for resources given by the <code title="rel-icon"><a href="#rel-icon">icon</a></code> keyword. However, for the purposes of
  <a href="semantics.html#concept-link-type-sniffing">determining the type of the
  resource</a>, user agents must expect the resource to be an image.</p>

  </div><p>The <dfn id="attr-link-sizes" title="attr-link-sizes"><code>sizes</code></dfn>
  attribute gives the sizes of icons for visual media.</p><p>If specified, the attribute must have a value that is an
  <a href="common-microsyntaxes.html#unordered-set-of-unique-space-separated-tokens">unordered set of unique space-separated tokens</a>, which
  are <a href="infrastructure.html#ascii-case-insensitive">ASCII case-insensitive</a>. The values must all be
  either an <a href="infrastructure.html#ascii-case-insensitive">ASCII case-insensitive</a> match for the string
  "<code title="attr-link-sizes-any"><a href="#attr-link-sizes-any">any</a></code>", or a value that
  consists of two <a href="common-microsyntaxes.html#valid-non-negative-integer" title="valid non-negative integer">valid
  non-negative integers</a> that do not have a leading U+0030 DIGIT
  ZERO (0) character and that are separated by a single U+0078 LATIN
  SMALL LETTER X or U+0058 LATIN CAPITAL LETTER X character.</p><p>The keywords represent icon sizes.</p><div class="impl">

  <p>To parse and process the attribute's value, the user agent must
  first <a href="common-microsyntaxes.html#split-a-string-on-spaces" title="split a string on spaces">split the attribute's
  value on spaces</a>, and must then parse each resulting keyword
  to determine what it represents.</p>

  </div><p>The <dfn id="attr-link-sizes-any" title="attr-link-sizes-any"><code>any</code></dfn> keyword
  represents that the resource contains a scalable icon, e.g. as
  provided by an SVG image.</p><div class="impl">

  <p>Other keywords must be further parsed as follows to determine
  what they represent:</p>

  <ul><li><p>If the keyword doesn't contain exactly one U+0078 LATIN
   SMALL LETTER X or U+0058 LATIN CAPITAL LETTER X character, then
   this keyword doesn't represent anything. Abort these steps for that
   keyword.</p></li>

   <li><p>Let <var title="">width string</var> be the string before
   the "<code title="">x</code>" or "<code title="">X</code>".</p></li>

   <li><p>Let <var title="">height string</var> be the string after
   the "<code title="">x</code>" or "<code title="">X</code>".</p></li>

   <li><p>If either <var title="">width string</var> or <var title="">height string</var> start with a U+0030 DIGIT ZERO (0)
   character or contain any characters other than characters in the
   range U+0030 DIGIT ZERO (0) to U+0039 DIGIT NINE (9), then this
   keyword doesn't represent anything. Abort these steps for that
   keyword.</p></li>

   <li><p>Apply the <a href="common-microsyntaxes.html#rules-for-parsing-non-negative-integers">rules for parsing non-negative
   integers</a> to <var title="">width string</var> to obtain <var title="">width</var>.</p></li>

   <li><p>Apply the <a href="common-microsyntaxes.html#rules-for-parsing-non-negative-integers">rules for parsing non-negative
   integers</a> to <var title="">height string</var> to obtain <var title="">height</var>.</p></li>

   <li><p>The keyword represents that the resource contains a bitmap
   icon with a width of <var title="">width</var> device pixels and a
   height of <var title="">height</var> device pixels.</p></li>

  </ul></div><p>The keywords specified on the <code title="attr-link-sizes"><a href="#attr-link-sizes">sizes</a></code> attribute must not represent
  icon sizes that are not actually available in the linked
  resource.</p><div class="impl">

  <p>If the attribute is not specified, then the user agent must
  assume that the given icon is appropriate, but less appropriate than
  an icon of a known and appropriate size.</p>

  <p>In the absence of a <code><a href="semantics.html#the-link-element">link</a></code> with the <code title="rel-icon"><a href="#rel-icon">icon</a></code> keyword, for <code><a href="infrastructure.html#document">Document</a></code>s
  obtained over HTTP or HTTPS, user agents may instead attempt to
  <a href="fetching-resources.html#fetch">fetch</a> and use an icon with the <a href="urls.html#absolute-url">absolute
  URL</a> obtained by resolving the <a href="urls.html#url">URL</a> "<code title="">/favicon.ico</code>" against <a href="dom.html#the-document-s-address">the document's
  address</a>, as if the page had declared that icon using the
  <code title="rel-icon"><a href="#rel-icon">icon</a></code> keyword.</p>

  </div><div class="example">

   <p>The following snippet shows the top part of an application with
   several icons.</p>

   <pre>&lt;!DOCTYPE HTML&gt;
&lt;html&gt;
 &lt;head&gt;
  &lt;title&gt;lsForums &#8212; Inbox&lt;/title&gt;
  &lt;link rel=icon href=favicon.png sizes="16x16" type="image/png"&gt;
  &lt;link rel=icon href=windows.ico sizes="32x32 48x48" type="image/vnd.microsoft.icon"&gt;
  &lt;link rel=icon href=mac.icns sizes="128x128 512x512 8192x8192 32768x32768"&gt;
  &lt;link rel=icon href=iphone.png sizes="57x57" type="image/png"&gt;
  &lt;link rel=icon href=gnome.svg sizes="any" type="image/svg+xml"&gt;
  &lt;link rel=stylesheet href=lsforums.css&gt;
  &lt;script src=lsforums.js&gt;&lt;/script&gt;
  &lt;meta name=application-name content="lsForums"&gt;
 &lt;/head&gt;
 &lt;body&gt;
  ...</pre>

  </div><h5 id="link-type-license"><span class="secno">4.12.4.7 </span>Link type "<dfn title="rel-license"><code>license</code></dfn>"</h5><p>The <code title="rel-license"><a href="#link-type-license">license</a></code> keyword may be used
  with <code><a href="semantics.html#the-link-element">link</a></code>, <code><a href="text-level-semantics.html#the-a-element">a</a></code>, and <code><a href="the-map-element.html#the-area-element">area</a></code>
  elements. This keyword creates a <a href="#hyperlink">hyperlink</a>.</p><p>The <code title="rel-license"><a href="#link-type-license">license</a></code> keyword indicates
  that the referenced document provides the copyright license terms
  under which the main content of the current document is
  provided.</p><p>This specification does not specify how to distinguish between
  the main content of a document and content that is not deemed to be
  part of that main content. The distinction should be made clear to
  the user.</p><div class="example">

   <p>Consider a photo sharing site. A page on that site might
   describe and show a photograph, and the page might be marked up as
   follows:</p>

   <pre>&lt;!DOCTYPE HTML&gt;
&lt;html&gt;
 &lt;head&gt;
  &lt;title&gt;Exampl Pictures: Kissat&lt;/title&gt;
  &lt;link rel="stylesheet" href="/style/default"&gt;
 &lt;/head&gt;
 &lt;body&gt;
  &lt;h1&gt;Kissat&lt;/h1&gt;
  &lt;nav&gt;
   &lt;a href="../"&gt;Return to photo index&lt;/a&gt;
  &lt;/nav&gt;
  &lt;figure&gt;
   &lt;img src="/pix/39627052_fd8dcd98b5.jpg"&gt;
   &lt;figcaption&gt;Kissat&lt;/figcaption&gt;
  &lt;/figure&gt;
  &lt;p&gt;One of them has six toes!&lt;/p&gt;
  &lt;p&gt;&lt;small&gt;&lt;a rel="license" href="http://www.opensource.org/licenses/mit-license.php"&gt;MIT Licensed&lt;/a&gt;&lt;/small&gt;&lt;/p&gt;
  &lt;footer&gt;
   &lt;a href="/"&gt;Home&lt;/a&gt; | &lt;a href="../"&gt;Photo index&lt;/a&gt;
   &lt;p&gt;&lt;small&gt;&#169; copyright 2009 Exampl Pictures. All Rights Reserved.&lt;/small&gt;&lt;/p&gt;
  &lt;/footer&gt;
 &lt;/body&gt;
&lt;/html&gt;</pre>

   <p>In this case the <code title="rel-license"><a href="#link-type-license">license</a></code>
   applies to just the photo (the main content of the document), not
   the whole document. In particular not the design of the page
   itself, which is covered by the copyright given at the bottom of
   the document. This could be made clearer in the styling
   (e.g. making the license link prominently positioned near the
   photograph, while having the page copyright in light small text at
   the foot of the page.</p>

  </div><div class="impl">

  <p><strong>Synonyms</strong>: For historical reasons, user agents
  must also treat the keyword "<code title="">copyright</code>" like
  the <code title="rel-license"><a href="#link-type-license">license</a></code> keyword.</p>

  </div><h5 id="link-type-nofollow"><span class="secno">4.12.4.8 </span>Link type "<dfn title="rel-nofollow"><code>nofollow</code></dfn>"</h5><p>The <code title="rel-nofollow"><a href="#link-type-nofollow">nofollow</a></code> keyword may be
  used with <code><a href="text-level-semantics.html#the-a-element">a</a></code> and <code><a href="the-map-element.html#the-area-element">area</a></code> elements. This
  keyword does not create a <a href="#hyperlink">hyperlink</a>, but <a href="#hyperlink-annotation" title="hyperlink annotation">annotates</a> any other hyperlinks
  created by the element (the implied hyperlink, if no other keywords
  create one).</p><p>The <code title="rel-nofollow"><a href="#link-type-nofollow">nofollow</a></code> keyword indicates
  that the link is not endorsed by the original author or publisher of
  the page, or that the link to the referenced document was included
  primarily because of a commercial relationship between people
  affiliated with the two pages.</p><h5 id="link-type-noreferrer"><span class="secno">4.12.4.9 </span>Link type "<dfn title="rel-noreferrer"><code>noreferrer</code></dfn>"</h5><p>The <code title="rel-noreferrer"><a href="#link-type-noreferrer">noreferrer</a></code> keyword may be
  used with <code><a href="text-level-semantics.html#the-a-element">a</a></code> and <code><a href="the-map-element.html#the-area-element">area</a></code> elements. This
  keyword does not create a <a href="#hyperlink">hyperlink</a>, but <a href="#hyperlink-annotation" title="hyperlink annotation">annotates</a> any other hyperlinks
  created by the element (the implied hyperlink, if no other keywords
  create one).</p><p>It indicates that no referrer information is to be leaked when
  following the link.</p><div class="impl">

  <p>If a user agent follows a link defined by an <code><a href="text-level-semantics.html#the-a-element">a</a></code> or
  <code><a href="the-map-element.html#the-area-element">area</a></code> element that has the <code title="rel-noreferrer"><a href="#link-type-noreferrer">noreferrer</a></code> keyword, the user agent
  must not include a <code title="http-referer">Referer</code> (sic)
  HTTP header (<a href="fetching-resources.html#concept-http-equivalent-headers" title="concept-http-equivalent-headers">or
  equivalent</a> for other protocols) in the request.</p>

  <p>This keyword also <a href="browsers.html#noopener">causes the <code title="dom-opener">opener</code> attribute to remain null</a> if the
  hyperlink creates a new <a href="browsers.html#browsing-context">browsing context</a>.</p>

  </div><h5 id="link-type-pingback"><span class="secno">4.12.4.10 </span>Link type "<dfn title="rel-pingback"><code>pingback</code></dfn>"</h5><p>The <code title="rel-pingback"><a href="#link-type-pingback">pingback</a></code> keyword may be
  used with <code><a href="semantics.html#the-link-element">link</a></code> elements. This keyword creates an <a href="#external-resource-link" title="external resource link">external resource link</a>.</p><p>For the semantics of the <code title="rel-pingback"><a href="#link-type-pingback">pingback</a></code> keyword, see the Pingback 1.0
  specification. <a href="references.html#refsPINGBACK">[PINGBACK]</a></p><h5 id="link-type-prefetch"><span class="secno">4.12.4.11 </span>Link type "<dfn title="rel-prefetch"><code>prefetch</code></dfn>"</h5><p>The <code title="rel-prefetch"><a href="#link-type-prefetch">prefetch</a></code> keyword may be
  used with <code><a href="semantics.html#the-link-element">link</a></code>, <code><a href="text-level-semantics.html#the-a-element">a</a></code>, and <code><a href="the-map-element.html#the-area-element">area</a></code>
  elements. This keyword creates an <a href="#external-resource-link" title="external resource
  link">external resource link</a>.</p><p>The <code title="rel-prefetch"><a href="#link-type-prefetch">prefetch</a></code> keyword indicates
  that preemptively fetching and caching the specified resource is
  likely to be beneficial, as it is highly likely that the user will
  require this resource.</p><p>There is no default type for resources given by the <code title="rel-prefetch"><a href="#link-type-prefetch">prefetch</a></code> keyword.</p><h5 id="link-type-search"><span class="secno">4.12.4.12 </span>Link type "<dfn title="rel-search"><code>search</code></dfn>"</h5><p>The <code title="rel-search"><a href="#link-type-search">search</a></code> keyword may be used
  with <code><a href="semantics.html#the-link-element">link</a></code>, <code><a href="text-level-semantics.html#the-a-element">a</a></code>, and <code><a href="the-map-element.html#the-area-element">area</a></code>
  elements. This keyword creates a <a href="#hyperlink">hyperlink</a>.</p><p>The <code title="rel-search"><a href="#link-type-search">search</a></code> keyword indicates that
  the referenced document provides an interface specifically for
  searching the document and its related resources.</p><p class="note">OpenSearch description documents can be used with
  <code><a href="semantics.html#the-link-element">link</a></code> elements and the <code title="rel-search"><a href="#link-type-search">search</a></code> link type to enable user agents to
  autodiscover search interfaces. <a href="references.html#refsOPENSEARCH">[OPENSEARCH]</a></p><h5 id="link-type-sidebar"><span class="secno">4.12.4.13 </span>Link type "<dfn title="rel-sidebar"><code>sidebar</code></dfn>"</h5><p>The <code title="rel-sidebar"><a href="#link-type-sidebar">sidebar</a></code> keyword may be used
  with <code><a href="semantics.html#the-link-element">link</a></code>, <code><a href="text-level-semantics.html#the-a-element">a</a></code>, and <code><a href="the-map-element.html#the-area-element">area</a></code>
  elements. This keyword creates a <a href="#hyperlink">hyperlink</a>.</p><p>The <code title="rel-sidebar"><a href="#link-type-sidebar">sidebar</a></code> keyword indicates
  that the referenced document, if retrieved, is intended to be shown
  in a <a href="browsers.html#secondary-browsing-context">secondary browsing context</a> (if possible), instead
  of in the current <a href="browsers.html#browsing-context">browsing context</a>.</p><p>A <a href="#hyperlink">hyperlink</a> with the <code title="rel-sidebar"><a href="#link-type-sidebar">sidebar</a></code> keyword specified is a <dfn id="rel-sidebar-hyperlink" title="rel-sidebar-hyperlink">sidebar hyperlink</dfn>.</p><h5 id="link-type-stylesheet"><span class="secno">4.12.4.14 </span>Link type "<dfn title="rel-stylesheet"><code>stylesheet</code></dfn>"</h5><p>The <code title="rel-stylesheet"><a href="#link-type-stylesheet">stylesheet</a></code> keyword may be
  used with <code><a href="semantics.html#the-link-element">link</a></code> elements. This keyword creates an <a href="#external-resource-link" title="external resource link">external resource link</a> that
  contributes to the <a href="semantics.html#styling">styling processing model</a>.</p><p>The specified resource is a resource that describes how to
  present the document. Exactly how the resource is to be processed
  depends on the actual type of the resource.</p><p>If the <code title="rel-alternate"><a href="#rel-alternate">alternate</a></code> keyword is
  also specified on the <code><a href="semantics.html#the-link-element">link</a></code> element, then <dfn id="the-link-is-an-alternative-stylesheet">the link
  is an alternative stylesheet</dfn>; in this case, the <code title="attr-title"><a href="elements.html#the-title-attribute">title</a></code> attribute must be specified on the
  <code><a href="semantics.html#the-link-element">link</a></code> element, with a non-empty value.</p><p>The default type for resources given by the <code title="rel-stylesheet"><a href="#link-type-stylesheet">stylesheet</a></code> keyword is <code title="">text/css</code>.</p><div class="impl">

  <p>The appropriate time to <a href="semantics.html#concept-link-obtain" title="concept-link-obtain">obtain</a> the resource is when the
  <a href="#external-resource-link" title="external resource link">external resource link</a>
  is created or when its element is <a href="infrastructure.html#insert-an-element-into-a-document" title="insert an element
  into a document">inserted into a document</a>, whichever happens
  last. If the resource is <a href="#the-link-is-an-alternative-stylesheet" title="the link is an alternative
  stylesheet">an alternative stylesheet</a> then the user agent may
  defer obtaining the resource until it is part of the <span>preferred
  style sheet set</span>. <a href="references.html#refsCSSOM">[CSSOM]</a></p> 
  <p><strong>Quirk</strong>: If the document has been set to
  <a href="dom.html#quirks-mode">quirks mode</a>, has the <a href="origin-0.html#same-origin">same origin</a> as the
  <a href="urls.html#url">URL</a> of the external resource<!-- CVE-2010-0654 -->, and
  the <a href="fetching-resources.html#content-type" title="Content-Type">Content-Type metadata</a> of the
  external resource is not a supported style sheet type, the user
  agent must instead assume it to be <code title="">text/css</code>.</p>

  </div><h5 id="link-type-tag"><span class="secno">4.12.4.15 </span>Link type "<dfn title="rel-tag"><code>tag</code></dfn>"</h5><p>The <code title="rel-tag"><a href="#link-type-tag">tag</a></code> keyword may be used
  with <code><a href="semantics.html#the-link-element">link</a></code>, <code><a href="text-level-semantics.html#the-a-element">a</a></code>, and <code><a href="the-map-element.html#the-area-element">area</a></code>
  elements. This keyword creates a <a href="#hyperlink">hyperlink</a>.</p><p>The <code title="rel-tag"><a href="#link-type-tag">tag</a></code> keyword indicates that the
  <em>tag</em> that the referenced document represents applies to the
  current document.</p><p class="note">Since it indicates that the tag <em>applies to the
  current document</em>, it would be inappropriate to use this keyword
  in the markup of a <a href="#tag-cloud">tag cloud</a>, which lists
  the popular tag across a set of pages.</p><h5 id="sequential-link-types"><span class="secno">4.12.4.16 </span>Sequential link types</h5><p>Some documents form part of a sequence of documents.</p><p>A sequence of documents is one where each document can have a
  <em>previous sibling</em> and a <em>next sibling</em>. A document
  with no previous sibling is the start of its sequence, a document
  with no next sibling is the end of its sequence.</p><p>A document may be part of multiple sequences.</p><h6 id="link-type-next"><span class="secno">4.12.4.16.1 </span>Link type "<dfn title="rel-next"><code>next</code></dfn>"</h6><p>The <code title="rel-next"><a href="#link-type-next">next</a></code> keyword may be used with
  <code><a href="semantics.html#the-link-element">link</a></code>, <code><a href="text-level-semantics.html#the-a-element">a</a></code>, and <code><a href="the-map-element.html#the-area-element">area</a></code>
  elements. This keyword creates a <a href="#hyperlink">hyperlink</a>.</p><p>The <code title="rel-next"><a href="#link-type-next">next</a></code> keyword indicates that the
  document is part of a sequence, and that the link is leading to the
  document that is the next logical document in the sequence.</p><h6 id="link-type-prev"><span class="secno">4.12.4.16.2 </span>Link type "<dfn title="rel-prev"><code>prev</code></dfn>"</h6><p>The <code title="rel-prev"><a href="#link-type-prev">prev</a></code> keyword may be used with
  <code><a href="semantics.html#the-link-element">link</a></code>, <code><a href="text-level-semantics.html#the-a-element">a</a></code>, and <code><a href="the-map-element.html#the-area-element">area</a></code>
  elements. This keyword creates a <a href="#hyperlink">hyperlink</a>.</p><p>The <code title="rel-prev"><a href="#link-type-prev">prev</a></code> keyword indicates that the
  document is part of a sequence, and that the link is leading to the
  document that is the previous logical document in the sequence.</p><div class="impl">

  <p><strong>Synonyms</strong>: For historical reasons, user agents
  must also treat the keyword "<code title="">previous</code>" like
  the <code title="rel-prev"><a href="#link-type-prev">prev</a></code> keyword.</p>

  </div><h5 id="other-link-types"><span class="secno">4.12.4.17 </span>Other link types</h5><p><dfn id="concept-rel-extensions" title="concept-rel-extensions">Extensions to the predefined
  set of link types</dfn> may be registered in the <a href="http://microformats.org/wiki/existing-rel-values">Microformats wiki existing-rel-values page</a>. <a href="references.html#refsMFREL">[MFREL]</a></p><p>Anyone is free to edit the <span title="">Microformats wiki
  existing-rel-values page</span> at any time to add a type. Extension
  types must be specified with the following information:</p><dl><dt>Keyword</dt>

   <dd>

    <p>The actual value being defined. The value should not be
    confusingly similar to any other defined value (e.g. differing
    only in case).</p>

    <p>If the value contains a U+003A COLON character (:), it must
    also be an <a href="urls.html#absolute-url">absolute URL</a>.</p>

   </dd>


   <dt>Effect on... <code><a href="semantics.html#the-link-element">link</a></code></dt>

   <dd>

    <p>One of the following:</p>

    <dl><dt>Not allowed</dt>

     <dd>The keyword must not be specified on <code><a href="semantics.html#the-link-element">link</a></code>
     elements.</dd>

     <dt>Hyperlink</dt>

     <dd>The keyword may be specified on a <code><a href="semantics.html#the-link-element">link</a></code> element;
     it creates a <a href="#hyperlink">hyperlink</a>.</dd>

     <dt>External Resource</dt>

     <dd>The keyword may be specified on a <code><a href="semantics.html#the-link-element">link</a></code> element;
     it creates an <a href="#external-resource-link">external resource link</a>.</dd>

    </dl></dd>


   <dt>Effect on... <code><a href="text-level-semantics.html#the-a-element">a</a></code> and <code><a href="the-map-element.html#the-area-element">area</a></code></dt>

   <dd>

    <p>One of the following:</p>

    <dl><dt>Not allowed</dt>

     <dd>The keyword must not be specified on <code><a href="text-level-semantics.html#the-a-element">a</a></code> and
     <code><a href="the-map-element.html#the-area-element">area</a></code> elements.</dd>

     <dt>Hyperlink</dt>

     <dd>The keyword may be specified on <code><a href="text-level-semantics.html#the-a-element">a</a></code> and
     <code><a href="the-map-element.html#the-area-element">area</a></code> elements; it creates a
     <a href="#hyperlink">hyperlink</a>.</dd>

     <dt>External Resource</dt>

     <dd>The keyword may be specified on a <code><a href="text-level-semantics.html#the-a-element">a</a></code> and
     <code><a href="the-map-element.html#the-area-element">area</a></code> elements; it creates an <a href="#external-resource-link">external resource
     link</a>.</dd>

     <dt>Hyperlink Annotation</dt>

     <dd>The keyword may be specified on a <code><a href="text-level-semantics.html#the-a-element">a</a></code> and
     <code><a href="the-map-element.html#the-area-element">area</a></code> elements; it <a href="#hyperlink-annotation" title="hyperlink
     annotation">annotates</a> other <a href="#hyperlink" title="hyperlink">hyperlinks</a> created by the element.</dd>

    </dl></dd>


   <dt>Brief description</dt>

   <dd><p>A short non-normative description of what the keyword's
   meaning is.</p></dd>


   <dt>Specification</dt>

   <dd><p>A link to a more detailed description of the keyword's
   semantics and requirements. It could be another page on the Wiki,
   or a link to an external page.</p></dd>


   <dt>Synonyms</dt>

   <dd><p>A list of other keyword values that have exactly the same
   processing requirements. Authors should not use the values defined
   to be synonyms, they are only intended to allow user agents to
   support legacy content. Anyone may remove synonyms that are not
   used in practice; only names that need to be processed as synonyms
   for compatibility with legacy content are to be registered in this
   way.</p></dd>


   <dt>Status</dt>

   <dd>

    <p>One of the following:</p>

    <dl><dt>Proposed</dt>

     <dd>The keyword has not received wide peer review and
     approval. Someone has proposed it and is, or soon will be, using
     it.</dd>

     <dt>Ratified</dt>

     <dd>The keyword has received wide peer review and approval. It
     has a specification that unambiguously defines how to handle
     pages that use the keyword, including when they use it in
     incorrect ways.</dd>

     <dt>Discontinued</dt>

     <dd>The keyword has received wide peer review and it has been
     found wanting. Existing pages are using this keyword, but new
     pages should avoid it. The "brief description" and
     "specification" entries will give details of what authors should
     use instead, if anything.</dd>

    </dl><p>If a keyword is found to be redundant with existing values, it
    should be removed and listed as a synonym for the existing
    value.</p>

    <p>If a keyword is registered in the "proposed" state for a
    period of a month or more without being used or specified, then it
    may be removed from the registry.</p>

    <p>If a keyword is added with the "proposed" status and found to
    be redundant with existing values, it should be removed and listed
    as a synonym for the existing value. If a keyword is added with
    the "proposed" status and found to be harmful, then it should be
    changed to "discontinued" status.</p>

    <p>Anyone can change the status at any time, but should only do so
    in accordance with the definitions above.</p>

   </dd>

  </dl><div class="impl">

  <p>Conformance checkers must use the information given on the <span title="">Microformats wiki existing-rel-values page</span> to
  establish if a value is allowed or not: values defined in this
  specification or marked as "proposed" or "ratified" must be accepted
  when used on the elements for which they apply as described in the
  "Effect on..." field, whereas values marked as "discontinued" or not
  listed in either this specification or on the aforementioned page
  must be rejected as invalid. Conformance checkers may cache this
  information (e.g. for performance reasons or to avoid the use of
  unreliable network connectivity).</p>

  <p>When an author uses a new type not defined by either this
  specification or the Wiki page, conformance checkers should offer to
  add the value to the Wiki, with the details described above, with
  the "proposed" status.</p>

  </div><p>Types defined as extensions in the <a href="http://microformats.org/wiki/existing-rel-values">Microformats
  wiki existing-rel-values page</a> with the status "proposed" or
  "ratified" may be used with the <code title="">rel</code> attribute
  on <code><a href="semantics.html#the-link-element">link</a></code>, <code><a href="text-level-semantics.html#the-a-element">a</a></code>, and <code><a href="the-map-element.html#the-area-element">area</a></code> elements
  in accordance to the "Effect on..." field. <a href="references.html#refsMFREL">[MFREL]</a></p><h3 id="common-idioms-without-dedicated-elements"><span class="secno">4.13 </span>Common idioms without dedicated elements</h3><h4 id="the-main-part-of-the-content"><span class="secno">4.13.1 </span>The main part of the content</h4><p>The main content of a page &#8212; not including headers and
  footers, navigation links, sidebars, advertisements, and so forth
  &#8212; can be marked up in a variety of ways, depending on the
  needs of the author.</p><p>The simplest solution is to not mark up the main content at all,
  and just leave it as implicit. Another way to think of this is that
  the <code><a href="sections.html#the-body-element">body</a></code> elements marks up the main content of the
  page, and the bits that aren't main content are excluded through the
  use of more appropriate elements like <code><a href="sections.html#the-aside-element">aside</a></code> and
  <code><a href="sections.html#the-nav-element">nav</a></code>.</p><div class="example">

   <p>Here is a short Web page marked up along this minimalistic
   school of thought. The main content is highlighted. Notice how all
   the <em>other</em> content in the <code><a href="sections.html#the-body-element">body</a></code> is marked up
   with elements to indicate that it's not part of the main content,
   in this case <code><a href="sections.html#the-header-element">header</a></code>, <code><a href="sections.html#the-nav-element">nav</a></code>, and
   <code><a href="sections.html#the-footer-element">footer</a></code>.</p>

   <pre>&lt;!DOCTYPE HTML&gt;
&lt;html&gt;
 &lt;head&gt;
  &lt;title&gt; My Toys &lt;/title&gt;
 &lt;/head&gt;
 &lt;body&gt;
  &lt;header&gt;
   &lt;h1&gt;My toys&lt;/h1&gt;
  &lt;/header&gt;
  &lt;nav&gt;
   &lt;p&gt;&lt;a href="/"&gt;Home&lt;/a&gt;&lt;/p&gt;
   &lt;p&gt;&lt;a href="/contact"&gt;Contact&lt;/a&gt;&lt;/p&gt;
  &lt;/nav&gt;
<strong>  &lt;p&gt;I really like my chained book and my telephone. I'm not such a
  fan of my big ball.&lt;/p&gt;
  &lt;p&gt;Another toy I like is my mirror.&lt;/p&gt;</strong>
  &lt;footer&gt;
   &lt;p&gt;&#169; copyright 2010 by the boy&lt;/p&gt;
  &lt;/footer&gt;
 &lt;/body&gt;
&lt;/html&gt;</pre>

  </div><p>If the main content is an independent unit of content that one
  could imagine syndicating independently, then the
  <code><a href="sections.html#the-article-element">article</a></code> element would be appropriate to mark up the
  main content of the document.</p><div class="example">

   <p>The document in the previous example is here recast as a blog
   post:</p>

   <pre>&lt;!DOCTYPE HTML&gt;
&lt;html&gt;
 &lt;head&gt;
  &lt;title&gt; The Boy Blog: My Toys &lt;/title&gt;
 &lt;/head&gt;
 &lt;body&gt;
  &lt;header&gt;
   &lt;h1&gt;The Boy Blog&lt;/h1&gt;
  &lt;/header&gt;
  &lt;nav&gt;
   &lt;p&gt;&lt;a href="/"&gt;Home&lt;/a&gt;&lt;/p&gt;
   &lt;p&gt;&lt;a href="/contact"&gt;Contact&lt;/a&gt;&lt;/p&gt;
  &lt;/nav&gt;
<strong>  &lt;article&gt;
   &lt;header&gt;
    &lt;h1&gt;My toys&lt;/h1&gt;
    &lt;p&gt;Published &lt;time pubdate datetime="2010-08-04"&gt;August 4th&lt;/time&gt;&lt;/p&gt;
   &lt;/header&gt;
   &lt;p&gt;I really like my chained book and my telephone. I'm not such a
   fan of my big ball.&lt;/p&gt;
   &lt;p&gt;Another toy I like is my mirror.&lt;/p&gt;
  &lt;/article&gt;</strong>
  &lt;footer&gt;
   &lt;p&gt;&#169; copyright 2010 by the boy&lt;/p&gt;
  &lt;/footer&gt;
 &lt;/body&gt;
&lt;/html&gt;</pre>

  </div><p>If the main content is not an independent unit of content so much
  as a section of a larger work, for instance a chapter, then the
  <code><a href="sections.html#the-section-element">section</a></code> element would be appropriate to mark up the
  main content of the document.</p><div class="example">

   <p>Here is the same document, case as a chapter in an online
   book:</p>

   <pre>&lt;!DOCTYPE HTML&gt;
&lt;html&gt;
 &lt;head&gt;
  &lt;title&gt; Chapter 2: My Toys &#8212; The Book of the Boy &lt;/title&gt;
 &lt;/head&gt;
 &lt;body&gt;
  &lt;header&gt;
   &lt;h1&gt;Chapter 2: My Toys&lt;/h1&gt;
  &lt;/header&gt;
  &lt;nav&gt;
   &lt;p&gt;&lt;a href="/"&gt;Front Page&lt;/a&gt;&lt;/p&gt;
   &lt;p&gt;&lt;a href="/toc"&gt;Table of Contents&lt;/a&gt;&lt;/p&gt;
   &lt;p&gt;&lt;a href="/c1"&gt;Chapter 1&lt;/a&gt; &#8212; &lt;a href="/c3"&gt;Chapter 3&lt;/a&gt;&lt;/p&gt;
  &lt;/nav&gt;
<strong>  &lt;section&gt;
   &lt;p&gt;I really like my chained book and my telephone. I'm not such a
   fan of my big ball.&lt;/p&gt;
   &lt;p&gt;Another toy I like is my mirror.&lt;/p&gt;
  &lt;/section&gt;</strong>
  &lt;footer&gt;
   &lt;p&gt;&#169; copyright 2010 by the boy&lt;/p&gt;
  &lt;/footer&gt;
 &lt;/body&gt;
&lt;/html&gt;</pre>

  </div><p>If neither <code><a href="sections.html#the-article-element">article</a></code> nor <code><a href="sections.html#the-section-element">section</a></code> would be
  appropriate, but the main content still needs an explicit element,
  for example for styling purposes, then the <code><a href="grouping-content.html#the-div-element">div</a></code> element
  can be used.</p><div class="example">

   <p>This is the same as the original example, but using
   <code><a href="grouping-content.html#the-div-element">div</a></code> for the main content instead of leaving it
   implied:</p>

   <pre>&lt;!DOCTYPE HTML&gt;
&lt;html&gt;
 &lt;head&gt;
  &lt;title&gt; My Toys &lt;/title&gt;
  &lt;style&gt;
   body &gt; div { background: navy; color: yellow; }
  &lt;/style&gt;
 &lt;/head&gt;
 &lt;body&gt;
  &lt;header&gt;
   &lt;h1&gt;My toys&lt;/h1&gt;
  &lt;/header&gt;
  &lt;nav&gt;
   &lt;p&gt;&lt;a href="/"&gt;Home&lt;/a&gt;&lt;/p&gt;
   &lt;p&gt;&lt;a href="/contact"&gt;Contact&lt;/a&gt;&lt;/p&gt;
  &lt;/nav&gt;
<strong>  &lt;div&gt;
   &lt;p&gt;I really like my chained book and my telephone. I'm not such a
   fan of my big ball.&lt;/p&gt;
   &lt;p&gt;Another toy I like is my mirror.&lt;/p&gt;
  &lt;/div&gt;</strong>
  &lt;footer&gt;
   &lt;p&gt;&#169; copyright 2010 by the boy&lt;/p&gt;
  &lt;/footer&gt;
 &lt;/body&gt;
&lt;/html&gt;</pre>

  </div><h4 id="rel-up"><span class="secno">4.13.2 </span>Bread crumb navigation</h4><p>This specification does not provide a machine-readable way of
  describing bread-crumb navigation menus. Authors are encouraged to
  just use a series of links in a paragraph. The <code><a href="sections.html#the-nav-element">nav</a></code>
  element can be used to mark the section containing these
  paragraphs as being navigation blocks.</p><div class="example">

   <p>In the following example, the current page can be reached via
   two paths.</p>

   <pre>&lt;nav&gt;
 &lt;p&gt;
  &lt;a href="/"&gt;Main&lt;/a&gt; &gt;
  &lt;a href="/products/"&gt;Products&lt;/a&gt; &gt;
  &lt;a href="/products/dishwashers/"&gt;Dishwashers&lt;/a&gt; &gt;
  &lt;a&gt;Second hand&lt;/a&gt;
 &lt;/p&gt;
 &lt;p&gt;
  &lt;a href="/"&gt;Main&lt;/a&gt; &gt;
  &lt;a href="/second-hand/"&gt;Second hand&lt;/a&gt; &gt;
  &lt;a&gt;Dishwashers&lt;/a&gt;
 &lt;/p&gt;
&lt;/nav&gt;</pre>

  </div><h4 id="tag-clouds"><span class="secno">4.13.3 </span>Tag clouds</h4><p id="tag-cloud">This specification does not define any markup
  specifically for marking up lists of keywords that apply to a group
  of pages (also known as <i>tag clouds</i>). In general, authors are
  encouraged to either mark up such lists using <code><a href="grouping-content.html#the-ul-element">ul</a></code>
  elements with explicit inline counts that are then hidden and turned
  into a presentational effect using a style sheet, or to use SVG.</p><div class="example">

   <p>Here, three tags are included in a short tag cloud:</p>

   <pre>&lt;style&gt;
@media screen, print, handheld, tv {
  /* should be ignored by non-visual browsers */
  .tag-cloud &gt; li &gt; span { display: none; }
  .tag-cloud &gt; li { display: inline; }
  .tag-cloud-1 { font-size: 0.7em; }
  .tag-cloud-2 { font-size: 0.9em; }
  .tag-cloud-3 { font-size: 1.1em; }
  .tag-cloud-4 { font-size: 1.3em; }
  .tag-cloud-5 { font-size: 1.5em; }
}
&lt;/style&gt;
...
&lt;ul class="tag-cloud"&gt;
 &lt;li class="tag-cloud-4"&gt;&lt;a title="28 instances" href="/t/apple"&gt;apple&lt;/a&gt; &lt;span&gt;(popular)&lt;/span&gt;
 &lt;li class="tag-cloud-2"&gt;&lt;a title="6 instances"  href="/t/kiwi"&gt;kiwi&lt;/a&gt; &lt;span&gt;(rare)&lt;/span&gt;
 &lt;li class="tag-cloud-5"&gt;&lt;a title="41 instances" href="/t/pear"&gt;pear&lt;/a&gt; &lt;span&gt;(very popular)&lt;/span&gt;
&lt;/ul&gt;</pre>

   <p>The actual frequency of each tag is given using the <code title="attr-title"><a href="elements.html#the-title-attribute">title</a></code> attribute. A CSS style sheet is
   provided to convert the markup into a cloud of differently-sized
   words, but for user agents that do not support CSS or are not
   visual, the markup contains annotations like "(popular)" or
   "(rare)" to categorize the various tags by frequency, thus enabling
   all users to benefit from the information.</p>

   <p>The <code><a href="grouping-content.html#the-ul-element">ul</a></code> element is used (rather than
   <code><a href="grouping-content.html#the-ol-element">ol</a></code>) because the order is not particularly important:
   while the list is in fact ordered alphabetically, it would convey
   the same information if ordered by, say, the length of the tag.</p>

   <p>The <code title="rel-tag"><a href="#link-type-tag">tag</a></code> <code title="attr-hyperlink-rel"><a href="#attr-hyperlink-rel">rel</a></code>-keyword is <em>not</em> used
   on these <code><a href="text-level-semantics.html#the-a-element">a</a></code> elements because they do not represent tags
   that apply to the page itself; they are just part of an index
   listing the tags themselves.</p>

  </div><h4 id="conversations"><span class="secno">4.13.4 </span>Conversations</h4><p>This specification does not define a specific element for marking
  up conversations, meeting minutes, chat transcripts, dialogues in
  screenplays, instant message logs, and other situations where
  different players take turns in discourse.</p><p>Instead, authors are encouraged to mark up conversations using
  <code><a href="grouping-content.html#the-p-element">p</a></code> elements and punctuation. Authors who need to mark
  the speaker for styling purposes are encouraged to use
  <code><a href="text-level-semantics.html#the-span-element">span</a></code> or <code><a href="text-level-semantics.html#the-b-element">b</a></code>. Paragraphs with their text
  wrapped in the <code><a href="text-level-semantics.html#the-i-element">i</a></code> element can be used for marking up
  stage directions.</p><div class="example">

   <p>This example demonstrates this using an extract from Abbot and
   Costello's famous sketch, <cite>Who's on first</cite>:</p>

<pre>&lt;p&gt; Costello: Look, you gotta first baseman?
&lt;p&gt; Abbott: Certainly.
&lt;p&gt; Costello: Who's playing first?
&lt;p&gt; Abbott: That's right.
&lt;p&gt; Costello becomes exasperated.
&lt;p&gt; Costello: When you pay off the first baseman every month, who gets the money?
&lt;p&gt; Abbott: Every dollar of it.</pre>

  </div><div class="example">

   <p>The following extract shows how an IM conversation log could be
   marked up.</p>

   <pre>&lt;p&gt; &lt;time&gt;14:22&lt;/time&gt; &lt;b&gt;egof&lt;/b&gt; I'm not that nerdy, I've only seen 30% of the star trek episodes
&lt;p&gt; &lt;time&gt;14:23&lt;/time&gt; &lt;b&gt;kaj&lt;/b&gt; if you know what percentage of the star trek episodes you have seen, you are inarguably nerdy
&lt;p&gt; &lt;time&gt;14:23&lt;/time&gt; &lt;b&gt;egof&lt;/b&gt; it's unarguably
&lt;p&gt; &lt;time&gt;14:23&lt;/time&gt; &lt;i&gt;* kaj blinks&lt;/i&gt;
&lt;p&gt; &lt;time&gt;14:24&lt;/time&gt; &lt;b&gt;kaj&lt;/b&gt; you are not helping your case</pre>
   

  </div><h4 id="footnotes"><span class="secno">4.13.5 </span>Footnotes</h4><p>HTML does not have a dedicated mechanism for marking up
  footnotes. Here are the recommended alternatives.</p><hr><p>For short inline annotations, the <code title="attr-title"><a href="elements.html#the-title-attribute">title</a></code> attribute should be used.</p><div class="example">

   <p>In this example, two parts of a dialogue are annotated with
   footnote-like content using the <code title="attr-title"><a href="elements.html#the-title-attribute">title</a></code> attribute.</p>

   <pre>&lt;p&gt; &lt;b&gt;Customer&lt;/b&gt;: Hello! I wish to register a complaint. Hello. Miss?
&lt;p&gt; &lt;b&gt;Shopkeeper&lt;/b&gt;: <strong>&lt;span title="Colloquial pronunciation of 'What do you'"</strong>
&gt;Watcha&lt;/span&gt; mean, miss?
&lt;p&gt; &lt;b&gt;Customer&lt;/b&gt;: Uh, I'm sorry, I have a cold. I wish to make a complaint.
&lt;p&gt; &lt;b&gt;Shopkeeper&lt;/b&gt;: Sorry, &lt;span <strong>title="This is, of course, a lie."</strong>&gt;we're
closing for lunch&lt;/span&gt;.</pre>

  </div><hr><p>For longer annotations, the <code><a href="text-level-semantics.html#the-a-element">a</a></code> element should be
  used, pointing to an element later in the document. The convention
  is that the contents of the link be a number in square brackets.</p><div class="example">

   <p>In this example, a footnote in the dialogue links to a paragraph
   below the dialogue. The paragraph then reciprocally links back to the
   dialogue, allowing the user to return to the location of the
   footnote.</p>

   <pre>&lt;p&gt; Announcer: Number 16: The &lt;i&gt;hand&lt;/i&gt;.
&lt;p&gt; Interviewer: Good evening. I have with me in the studio tonight
Mr Norman St John Polevaulter, who for the past few years has been
contradicting people. Mr Polevaulter, why &lt;em&gt;do&lt;/em&gt; you
contradict people?
&lt;p&gt; Norman: I don't. &lt;sup&gt;&lt;a href="#fn1" id="r1"&gt;[1]&lt;/a&gt;&lt;/sup&gt;
&lt;p&gt; Interviewer: You told me you did!
<em>...</em>
&lt;section&gt;
 &lt;p id="fn1"&gt;&lt;a href="#r1"&gt;[1]&lt;/a&gt; This is, naturally, a lie,
 but paradoxically if it were true he could not say so without
 contradicting the interviewer and thus making it false.&lt;/p&gt;
&lt;/section&gt;</pre>

  </div><hr><p>For side notes, longer annotations that apply to entire sections
  of the text rather than just specific words or sentences, the
  <code><a href="sections.html#the-aside-element">aside</a></code> element should be used.</p><div class="example">

   <p>In this example, a sidebar is given after a dialogue, giving it
   some context.</p>

   <pre>&lt;p&gt; &lt;span class="speaker"&gt;Customer&lt;/span&gt;: I will not buy this record, it is scratched.
&lt;p&gt; &lt;span class="speaker"&gt;Shopkeeper&lt;/span&gt;: I'm sorry?
&lt;p&gt; &lt;span class="speaker"&gt;Customer&lt;/span&gt;: I will not buy this record, it is scratched.
&lt;p&gt; &lt;span class="speaker"&gt;Shopkeeper&lt;/span&gt;: No no no, this's'a tobacconist's.
&lt;aside&gt;
 &lt;p&gt;In 1970, the British Empire lay in ruins, and foreign
 nationalists frequented the streets &#8212; many of them Hungarians
 (not the streets &#8212; the foreign nationals). Sadly, Alexander
 Yalt has been publishing incompetently-written phrase books.
&lt;/aside&gt;</pre>

  </div><hr><p>For figures or tables, footnotes can be included in the relevant
  <code><a href="grouping-content.html#the-figcaption-element">figcaption</a></code> or <code><a href="tabular-data.html#the-caption-element">caption</a></code> element, or in
  surrounding prose.</p><div class="example">

   <p>In this example, a  table has cells with footnotes
   that are given in prose. A <code><a href="grouping-content.html#the-figure-element">figure</a></code> element is used to
   give a single legend to the combination of the table and its
   footnotes.</p>

   <pre>&lt;figure&gt;
 &lt;figcaption&gt;Table 1. Alternative activities for knights.&lt;/figcaption&gt;
 &lt;table&gt;
  &lt;tr&gt;
   &lt;th&gt; Activity
   &lt;th&gt; Location
   &lt;th&gt; Cost
  &lt;tr&gt;
   &lt;td&gt; Dance
   &lt;td&gt; Wherever possible
   &lt;td&gt; &#163;0&lt;sup&gt;&lt;a href="#fn1"&gt;1&lt;/a&gt;&lt;/sup&gt;
  &lt;tr&gt;
   &lt;td&gt; Routines, chorus scenes&lt;sup&gt;&lt;a href="#fn2"&gt;2&lt;/a&gt;&lt;/sup&gt;
   &lt;td&gt; Undisclosed
   &lt;td&gt; Undisclosed
  &lt;tr&gt;
   &lt;td&gt; Dining&lt;sup&gt;&lt;a href="#fn3"&gt;3&lt;/a&gt;&lt;/sup&gt;
   &lt;td&gt; Camelot
   &lt;td&gt; Cost of ham, jam, and spam&lt;sup&gt;&lt;a href="#fn4"&gt;4&lt;/a&gt;&lt;/sup&gt;
 &lt;/table&gt;
 &lt;p id="fn1"&gt;1. Assumed.&lt;/p&gt;
 &lt;p id="fn2"&gt;2. Footwork impeccable.&lt;/p&gt;
 &lt;p id="fn3"&gt;3. Quality described as "well".&lt;/p&gt;
 &lt;p id="fn4"&gt;4. A lot.&lt;/p&gt;
&lt;/figure&gt;</pre>

  </div><div class="impl">

  <h3 id="matching-html-elements-using-selectors"><span class="secno">4.14 </span>Matching HTML elements using selectors</h3>

  <h4 id="selectors"><span class="secno">4.14.1 </span>Case-sensitivity</h4>

  <p>Attribute and element <em>names</em> of <a href="infrastructure.html#html-elements">HTML
  elements</a> in <a href="dom.html#html-documents">HTML documents</a> must be treated as
  <a href="infrastructure.html#ascii-case-insensitive">ASCII case-insensitive</a>.</p>

  <p>Classes from the <code title="attr-class"><a href="elements.html#classes">class</a></code> attribute
  of <a href="infrastructure.html#html-elements">HTML elements</a> in documents that are in <a href="dom.html#quirks-mode">quirks
  mode</a> must be treated as <a href="infrastructure.html#ascii-case-insensitive">ASCII
  case-insensitive</a>.</p>

  <p>Attribute selectors on an <a href="infrastructure.html#html-elements" title="HTML elements">HTML
  element</a> in an <a href="dom.html#html-documents" title="HTML documents">HTML
  document</a> must treat the <em>values</em> of attributes with
  the following names as <a href="infrastructure.html#ascii-case-insensitive">ASCII case-insensitive</a>, with one
  exception as noted below:</p>

  
  
  <ul class="brief"><li><code title="">accept</code>
   </li><li><code title="">accept-charset</code>
   </li><li><code title="">align</code>
   </li><li><code title="">alink</code>
   </li><li><code title="">axis</code>
   </li><li><code title="">bgcolor</code>
   </li><li><code title="">charset</code>
   </li><li><code title="">checked</code>
   </li><li><code title="">clear</code>
   </li><li><code title="">codetype</code>
   </li><li><code title="">color</code>
   </li><li><code title="">compact</code>
   </li><li><code title="">declare</code>
   </li><li><code title="">defer</code>
   </li><li><code title="">dir</code>
   </li><li><code title="">direction</code> 
   </li><li><code title="">disabled</code>
   </li><li><code title="">enctype</code>
   </li><li><code title="">face</code>
   </li><li><code title="">frame</code>
   </li><li><code title="">hreflang</code>
   </li><li><code title="">http-equiv</code>
   </li><li><code title="">lang</code>
   </li><li><code title="">language</code>
   </li><li><code title="">link</code>
   </li><li><code title="">media</code>
   </li><li><code title="">method</code>
   </li><li><code title="">multiple</code>
   </li><li><code title="">nohref</code>
   </li><li><code title="">noresize</code>
   </li><li><code title="">noshade</code>
   </li><li><code title="">nowrap</code>
   </li><li><code title="">readonly</code>
   </li><li><code title="">rel</code>
   </li><li><code title="">rev</code>
   </li><li><code title="">rules</code>
   </li><li><code title="">scope</code>
   </li><li><code title="">scrolling</code>
   </li><li><code title="">selected</code>
   </li><li><code title="">shape</code>
   </li><li><code title="">target</code>
   </li><li><code title="">text</code>
   </li><li><code title="">type</code> (except as specified below)
   </li><li><code title="">valign</code>
   </li><li><code title="">valuetype</code>
   </li><li><code title="">vlink</code>
  </li></ul><p>All other attribute values on <a href="infrastructure.html#html-elements">HTML elements</a> must be
  treated as <a href="infrastructure.html#case-sensitive">case-sensitive</a>.</p>

  <p>The exception to the list above is the <code title="attr-ol-type"><a href="grouping-content.html#attr-ol-type">type</a></code> attribute on <code><a href="grouping-content.html#the-ol-element">ol</a></code>
  elements, which must be treated as <a href="infrastructure.html#case-sensitive">case-sensitive</a>.</p>


  <h4 id="pseudo-classes"><span class="secno">4.14.2 </span>Pseudo-classes</h4>

  <p>There are a number of dynamic selectors that can be used with
  HTML. This section defines when these selectors match HTML
  elements.</p>

  <dl><dt><dfn id="selector-link" title="selector-link"><code>:link</code></dfn></dt>
   <dt><dfn id="selector-visited" title="selector-visited"><code>:visited</code></dfn></dt>

   <dd>

    <p>All <code><a href="text-level-semantics.html#the-a-element">a</a></code> elements that have an <code title="attr-hyperlink-href"><a href="#attr-hyperlink-href">href</a></code> attribute, all
    <code><a href="the-map-element.html#the-area-element">area</a></code> elements that have an <code title="attr-hyperlink-href"><a href="#attr-hyperlink-href">href</a></code> attribute, and all
    <code><a href="semantics.html#the-link-element">link</a></code> elements that have an <code title="attr-link-href"><a href="semantics.html#attr-link-href">href</a></code> attribute, must match one of
    <code title="selector-link"><a href="#selector-link">:link</a></code> and <code title="selector-visited"><a href="#selector-visited">:visited</a></code>.</p>

    <p>Other specifications might apply more specific rules regarding
    how these elements are to match these pseudo-elements, to mitigate
    some privacy concerns that apply with straightforward
    implementations of this requirement.</p>

   </dd>


   <dt><dfn id="selector-active" title="selector-active"><code>:active</code></dfn></dt>

   <dd>

    <p>The <code title="selector-active"><a href="#selector-active">:active</a></code> pseudo-class
    is defined to match an element <q cite="http://dev.w3.org/csswg/selectors3/#the-user-action-pseudo-classes-hover-act">while
    an element is <i>being activated</i> by the user</q>. For the
    purposes of defining the <code title="selector-active"><a href="#selector-active">:active</a></code> pseudo-class only, an HTML
    user agent must consider an element as <i>being activated</i> if
    it is:</p>

    <ul><li>

      <p>An element falling into one of the following categories
      between the time the user begins to indicate an intent to
      trigger the element's <a href="content-models.html#activation-behavior">activation behavior</a> and
      either the time the user stops indicating an intent to trigger
      the element's <a href="content-models.html#activation-behavior">activation behavior</a>, or the time the
      element's <a href="content-models.html#activation-behavior">activation behavior</a> has finished running,
      which ever comes first:</p>

      <ul><li><code><a href="text-level-semantics.html#the-a-element">a</a></code> elements that have an <code title="attr-hyperlink-href"><a href="#attr-hyperlink-href">href</a></code> attribute</li>

       <li><code><a href="the-map-element.html#the-area-element">area</a></code> elements that have an <code title="attr-hyperlink-href"><a href="#attr-hyperlink-href">href</a></code> attribute</li>

       <li><code><a href="semantics.html#the-link-element">link</a></code> elements that have an <code title="attr-link-href"><a href="semantics.html#attr-link-href">href</a></code> attribute</li>

       <li><code><a href="the-button-element.html#the-button-element">button</a></code> elements that are not <a href="association-of-controls-and-forms.html#concept-fe-disabled" title="concept-fe-disabled">disabled</a></li>

       <li><code><a href="the-input-element.html#the-input-element">input</a></code> elements whose <code title="attr-input-type"><a href="the-input-element.html#attr-input-type">type</a></code> attribute is in the <a href="number-state.html#submit-button-state" title="attr-input-type-submit">Submit Button</a>, <a href="number-state.html#image-button-state" title="attr-input-type-image">Image Button</a>, <a href="number-state.html#reset-button-state" title="attr-input-type-reset">Reset Button</a>, or <a href="number-state.html#button-state" title="attr-input-type-button">Button</a> state</li>

       <li><code><a href="interactive-elements.html#the-command-element">command</a></code> elements that do not have a <code title="attr-command-disabled"><a href="interactive-elements.html#attr-command-disabled">disabled</a></code> attribute</li>

       <li>elements that are <a href="editing.html#specially-focusable">specially focusable</a></li>

      </ul><p class="example">For example, if the user is using a keyboard
      to push a <code><a href="the-button-element.html#the-button-element">button</a></code> element by pressing the space bar,
      the element would match this pseudo-class in between the time
      that the element received the <code title="event-keydown">keydown</code> event and the time the
      element received the <code title="event-keyup">keyup</code>
      event.</p>

     </li>

     <li>

      <p>An element that the user indicates using a pointing device
      while that pointing device is in the "down" state (e.g. for a
      mouse, between the time the mouse button is pressed and the time
      it is depressed).</p>

     </li>

     <li>

      <p>An element that has a descendant that is currently matching
      the <code title="selector-active"><a href="#selector-active">:active</a></code>
      pseudo-class.</p>

     </li>

    </ul></dd>


   <dt><dfn id="selector-enabled" title="selector-enabled"><code>:enabled</code></dfn></dt>

   <dd>

    <p>The <code title="selector-enabled"><a href="#selector-enabled">:enabled</a></code> pseudo-class
    must match any element falling into one of the following
    categories:</p>

    <ul><li><code><a href="text-level-semantics.html#the-a-element">a</a></code> elements that have an <code title="attr-hyperlink-href"><a href="#attr-hyperlink-href">href</a></code> attribute</li>

     <li><code><a href="the-map-element.html#the-area-element">area</a></code> elements that have an <code title="attr-hyperlink-href"><a href="#attr-hyperlink-href">href</a></code> attribute</li>

     <li><code><a href="semantics.html#the-link-element">link</a></code> elements that have an <code title="attr-link-href"><a href="semantics.html#attr-link-href">href</a></code> attribute</li>

     <li><code><a href="the-button-element.html#the-button-element">button</a></code> elements that are not <a href="association-of-controls-and-forms.html#concept-fe-disabled" title="concept-fe-disabled">disabled</a></li>

     <li><code><a href="the-input-element.html#the-input-element">input</a></code> elements whose <code title="attr-input-type"><a href="the-input-element.html#attr-input-type">type</a></code> attribute are not in the
     <a href="states-of-the-type-attribute.html#hidden-state" title="attr-input-type-hidden">Hidden</a> state and that
     are not <a href="association-of-controls-and-forms.html#concept-fe-disabled" title="concept-fe-disabled">disabled</a></li>

     <li><code><a href="the-button-element.html#the-select-element">select</a></code> elements that are not <a href="association-of-controls-and-forms.html#concept-fe-disabled" title="concept-fe-disabled">disabled</a></li>

     <li><code><a href="the-button-element.html#the-textarea-element">textarea</a></code> elements that are not <a href="association-of-controls-and-forms.html#concept-fe-disabled" title="concept-fe-disabled">disabled</a></li>

     <li><code><a href="the-button-element.html#the-optgroup-element">optgroup</a></code> elements that are not <span title="concept-optgroup-disabled">disabled</span></li>

     <li><code><a href="the-button-element.html#the-option-element">option</a></code> elements that are not <a href="the-button-element.html#concept-option-disabled" title="concept-option-disabled">disabled</a></li>

     <li><code><a href="interactive-elements.html#the-command-element">command</a></code> elements that do not have a <code title="attr-command-disabled"><a href="interactive-elements.html#attr-command-disabled">disabled</a></code> attribute</li>

     <li><code><a href="grouping-content.html#the-li-element">li</a></code> elements that are children of
     <code><a href="interactive-elements.html#the-menu-element">menu</a></code> elements, and that have a child element that
     defines a <a href="commands.html#concept-command" title="concept-command">command</a>, if the
     first such element's <a href="commands.html#command-facet-disabledstate" title="command-facet-disabledstate">Disabled State</a> facet
     is false (not disabled)</li>

     <li><code><a href="forms.html#the-fieldset-element">fieldset</a></code> elements that do not have a <code title="attr-fieldset-disabled"><a href="forms.html#attr-fieldset-disabled">disabled</a></code> attribute</li>

    </ul></dd>


   <dt><dfn id="selector-disabled" title="selector-disabled"><code>:disabled</code></dfn></dt>

   <dd>

    <p>The <code title="selector-disabled"><a href="#selector-disabled">:disabled</a></code>
    pseudo-class must match any element falling into one of the
    following categories:</p>

    <ul><li><code><a href="the-button-element.html#the-button-element">button</a></code> elements that are <a href="association-of-controls-and-forms.html#concept-fe-disabled" title="concept-fe-disabled">disabled</a></li>

     <li><code><a href="the-input-element.html#the-input-element">input</a></code> elements whose <code title="attr-input-type"><a href="the-input-element.html#attr-input-type">type</a></code> attribute are not in the
     <a href="states-of-the-type-attribute.html#hidden-state" title="attr-input-type-hidden">Hidden</a> state and that
     are <a href="association-of-controls-and-forms.html#concept-fe-disabled" title="concept-fe-disabled">disabled</a></li>

     <li><code><a href="the-button-element.html#the-select-element">select</a></code> elements that are <a href="association-of-controls-and-forms.html#concept-fe-disabled" title="concept-fe-disabled">disabled</a></li>

     <li><code><a href="the-button-element.html#the-textarea-element">textarea</a></code> elements that are <a href="association-of-controls-and-forms.html#concept-fe-disabled" title="concept-fe-disabled">disabled</a></li>

     <li><code><a href="the-button-element.html#the-optgroup-element">optgroup</a></code> elements that are <span title="concept-optgroup-disabled">disabled</span></li>

     <li><code><a href="the-button-element.html#the-option-element">option</a></code> elements that are <a href="the-button-element.html#concept-option-disabled" title="concept-option-disabled">disabled</a></li>

     <li><code><a href="interactive-elements.html#the-command-element">command</a></code> elements that have a <code title="attr-command-disabled"><a href="interactive-elements.html#attr-command-disabled">disabled</a></code> attribute</li>

     <li><code><a href="grouping-content.html#the-li-element">li</a></code> elements that are children of
     <code><a href="interactive-elements.html#the-menu-element">menu</a></code> elements, and that have a child element that
     defines a <a href="commands.html#concept-command" title="concept-command">command</a>, if the
     first such element's <a href="commands.html#command-facet-disabledstate" title="command-facet-disabledstate">Disabled State</a> facet
     is true (disabled)</li>

     <li><code><a href="forms.html#the-fieldset-element">fieldset</a></code> elements that have a <code title="attr-fieldset-disabled"><a href="forms.html#attr-fieldset-disabled">disabled</a></code> attribute</li>

    </ul></dd>


   <dt><dfn id="selector-checked" title="selector-checked"><code>:checked</code></dfn></dt>

   <dd>

    <p>The <code title="selector-checked"><a href="#selector-checked">:checked</a></code> pseudo-class
    must match any element falling into one of the following
    categories:</p>

    <ul><li><code><a href="the-input-element.html#the-input-element">input</a></code> elements whose <code title="attr-input-type"><a href="the-input-element.html#attr-input-type">type</a></code> attribute is in the <a href="number-state.html#checkbox-state" title="attr-input-type-checkbox">Checkbox</a> state and whose
     <a href="association-of-controls-and-forms.html#concept-fe-checked" title="concept-fe-checked">checkedness</a> state is
     true</li>

     <li><code><a href="the-input-element.html#the-input-element">input</a></code> elements whose <code title="attr-input-type"><a href="the-input-element.html#attr-input-type">type</a></code> attribute is in the <a href="number-state.html#radio-button-state" title="attr-input-type-radio">Radio Button</a> state and whose
     <a href="association-of-controls-and-forms.html#concept-fe-checked" title="concept-fe-checked">checkedness</a> state is
     true</li>

     <li><code><a href="the-button-element.html#the-option-element">option</a></code> elements whose <a href="the-button-element.html#concept-option-selectedness" title="concept-option-selectedness">selectedness</a> is
     true</li>

     <li><code><a href="interactive-elements.html#the-command-element">command</a></code> elements whose <code title="attr-command-type"><a href="interactive-elements.html#attr-command-type">type</a></code> attribute is in the <a href="interactive-elements.html#attr-command-type-state-checkbox" title="attr-command-type-state-checkbox">Checkbox</a> state
     and that have a <code title="attr-command-checked"><a href="interactive-elements.html#attr-command-checked">checked</a></code>
     attribute</li>

     <li><code><a href="interactive-elements.html#the-command-element">command</a></code> elements whose <code title="attr-command-type"><a href="interactive-elements.html#attr-command-type">type</a></code> attribute is in the <a href="interactive-elements.html#attr-command-type-state-radio" title="attr-command-type-state-radio">Radio</a> state and that
     have a <code title="attr-command-checked"><a href="interactive-elements.html#attr-command-checked">checked</a></code>
     attribute</li>

    </ul></dd>


   <dt><dfn id="selector-indeterminate" title="selector-indeterminate"><code>:indeterminate</code></dfn></dt>

   <dd>

    

    <p>The <code title="selector-indeterminate"><a href="#selector-indeterminate">:indeterminate</a></code>
    pseudo-class must match any element falling into one of the
    following categories:</p>

    <ul><li><code><a href="the-input-element.html#the-input-element">input</a></code> elements whose <code title="attr-input-type"><a href="the-input-element.html#attr-input-type">type</a></code> attribute is in the <a href="number-state.html#checkbox-state" title="attr-input-type-checkbox">Checkbox</a> state and whose
     <code title="dom-input-indeterminate"><a href="the-input-element.html#dom-input-indeterminate">indeterminate</a></code> IDL
     attribute is set to true</li>

     <li><code><a href="the-button-element.html#the-progress-element">progress</a></code> elements with no <code title="attr-progress-value"><a href="the-button-element.html#attr-progress-value">value</a></code> content attribute</li>

    </ul></dd>


   <dt><dfn id="selector-default" title="selector-default"><code>:default</code></dfn></dt>

   <dd>

    <p>The <code title="selector-default"><a href="#selector-default">:default</a></code> pseudo-class
    must match any element falling into one of the following
    categories:</p>

    <ul><li><code><a href="the-button-element.html#the-button-element">button</a></code> elements that are their form's
     <a href="association-of-controls-and-forms.html#default-button">default button</a></li>

     <li><code><a href="the-input-element.html#the-input-element">input</a></code> elements whose <code title="attr-input-type"><a href="the-input-element.html#attr-input-type">type</a></code> attribute is in the <a href="number-state.html#submit-button-state" title="attr-input-type-submit">Submit Button</a> or <a href="number-state.html#image-button-state" title="attr-input-type-image">Image Button</a> state, and that
     are their form's <a href="association-of-controls-and-forms.html#default-button">default button</a></li>

     <li><code><a href="the-input-element.html#the-input-element">input</a></code> elements to which the <code title="attr-input-checked"><a href="the-input-element.html#attr-input-checked">checked</a></code> attribute applies and
     that have a <code title="attr-input-checked"><a href="the-input-element.html#attr-input-checked">checked</a></code>
     attribute</li>

     <li><code><a href="the-button-element.html#the-option-element">option</a></code> elements that have a <code title="attr-option-selected"><a href="the-button-element.html#attr-option-selected">selected</a></code> attribute</li>
    </ul></dd>


   <dt><dfn id="selector-valid" title="selector-valid"><code>:valid</code></dfn></dt>

   <dd>

    <p>The <code title="selector-valid"><a href="#selector-valid">:valid</a></code> pseudo-class
    must match all elements that are <a href="association-of-controls-and-forms.html#candidate-for-constraint-validation" title="candidate for
    constraint validation">candidates for constraint validation</a>
    and that <a href="association-of-controls-and-forms.html#concept-fv-valid" title="concept-fv-valid">satisfy their
    constraints</a>.</p>

   </dd>


   <dt><dfn id="selector-invalid" title="selector-invalid"><code>:invalid</code></dfn></dt>

   <dd>

    <p>The <code title="selector-invalid"><a href="#selector-invalid">:invalid</a></code> pseudo-class
    must match all elements that are <a href="association-of-controls-and-forms.html#candidate-for-constraint-validation" title="candidate for
    constraint validation">candidates for constraint validation</a>
    but that do not <a href="association-of-controls-and-forms.html#concept-fv-valid" title="concept-fv-valid">satisfy their
    constraints</a>.</p>

   </dd>


   <dt><dfn id="selector-in-range" title="selector-in-range"><code>:in-range</code></dfn></dt>

   <dd>

    <p>The <code title="selector-in-range"><a href="#selector-in-range">:in-range</a></code>
    pseudo-class must match all elements that are <a href="association-of-controls-and-forms.html#candidate-for-constraint-validation" title="candidate for constraint validation">candidates for
    constraint validation</a>, <a href="common-input-element-attributes.html#have-range-limitations">have range limitations</a>,
    and that are neither <a href="association-of-controls-and-forms.html#suffering-from-an-underflow">suffering from an underflow</a> nor
    <a href="association-of-controls-and-forms.html#suffering-from-an-overflow">suffering from an overflow</a>.</p>

   </dd>


   <dt><dfn id="selector-out-of-range" title="selector-out-of-range"><code>:out-of-range</code></dfn></dt>

   <dd>

    <p>The <code title="selector-out-of-range"><a href="#selector-out-of-range">:out-of-range</a></code>
    pseudo-class must match all elements that are <a href="association-of-controls-and-forms.html#candidate-for-constraint-validation" title="candidate for constraint validation">candidates for
    constraint validation</a>, <a href="common-input-element-attributes.html#have-range-limitations">have range limitations</a>,
    and that are either <a href="association-of-controls-and-forms.html#suffering-from-an-underflow">suffering from an underflow</a> or
    <a href="association-of-controls-and-forms.html#suffering-from-an-overflow">suffering from an overflow</a>.</p>

   </dd>


   <dt><dfn id="selector-required" title="selector-required"><code>:required</code></dfn></dt>

   <dd>

    <p>The <code title="selector-required"><a href="#selector-required">:required</a></code>
    pseudo-class must match any element falling into one of the
    following categories:</p>

    <ul><li><code><a href="the-input-element.html#the-input-element">input</a></code> elements that are <i title="concept-input-required"><a href="common-input-element-attributes.html#concept-input-required">required</a></i></li>

     <li><code><a href="the-button-element.html#the-select-element">select</a></code> elements that have a <code title="attr-select-required"><a href="the-button-element.html#attr-select-required">required</a></code>
     attribute</li>

     <li><code><a href="the-button-element.html#the-textarea-element">textarea</a></code> elements that have a <code title="attr-textarea-required"><a href="the-button-element.html#attr-textarea-required">required</a></code>
     attribute</li>

    </ul></dd>


   <dt><dfn id="selector-optional" title="selector-optional"><code>:optional</code></dfn></dt>

   <dd>

    <p>The <code title="selector-optional"><a href="#selector-optional">:optional</a></code>
    pseudo-class must match any element falling into one of the
    following categories:</p>

    <ul><li><code><a href="the-input-element.html#the-input-element">input</a></code> elements to which the <code title="attr-input-required"><a href="common-input-element-attributes.html#attr-input-required">required</a></code> attribute applies
     that are not <i title="concept-input-required"><a href="common-input-element-attributes.html#concept-input-required">required</a></i></li>

     <li><code><a href="the-button-element.html#the-select-element">select</a></code> elements that do not have a <code title="attr-select-required"><a href="the-button-element.html#attr-select-required">required</a></code> attribute</li>

     <li><code><a href="the-button-element.html#the-textarea-element">textarea</a></code> elements that do not have a <code title="attr-textarea-required"><a href="the-button-element.html#attr-textarea-required">required</a></code>
     attribute</li>

    </ul></dd>


   <dt><dfn id="selector-read-only" title="selector-read-only"><code>:read-only</code></dfn></dt>
   <dt><dfn id="selector-read-write" title="selector-read-write"><code>:read-write</code></dfn></dt>

   <dd>

    <p>The <code title="selector-read-write"><a href="#selector-read-write">:read-write</a></code>
    pseudo-class must match any element falling into one of the
    following categories:</p>

    <ul><li><code><a href="the-input-element.html#the-input-element">input</a></code> elements to which the <code title="attr-input-readonly"><a href="common-input-element-attributes.html#attr-input-readonly">readonly</a></code> attribute applies,
     but that are not <i title="concept-input-immutable"><a href="the-input-element.html#concept-input-immutable">immutable</a></i>
     (i.e. that do not have the <code title="attr-input-readonly"><a href="common-input-element-attributes.html#attr-input-readonly">readonly</a></code> attribute specified
     and that are not <a href="association-of-controls-and-forms.html#concept-fe-disabled" title="concept-fe-disabled">disabled</a>)</li>

     <li><code><a href="the-button-element.html#the-textarea-element">textarea</a></code> elements that do not have a <code title="attr-textarea-readonly"><a href="the-button-element.html#attr-textarea-readonly">readonly</a></code> attribute, and
     that are not <a href="association-of-controls-and-forms.html#concept-fe-disabled" title="concept-fe-disabled">disabled</a></li>

     <li>elements that are <a href="editing.html#editable">editable</a> and are neither
     <code><a href="the-input-element.html#the-input-element">input</a></code> elemenst nor <code><a href="the-button-element.html#the-textarea-element">textarea</a></code>
     elements</li>

    </ul><p>The <code title="selector-read-only"><a href="#selector-read-only">:read-only</a></code>
    pseudo-class must match all other <a href="infrastructure.html#html-elements">HTML elements</a>.</p>

   </dd>


   <dt><dfn id="selector-ltr" title="selector-ltr"><code>:ltr</code></dfn></dt>

   <dd>

    <p>The <code title="selector-ltr"><a href="#selector-ltr">:ltr</a></code> pseudo-class must
    match all elements whose <a href="elements.html#the-directionality" title="the
    directionality">directionality</a> is '<a href="elements.html#concept-ltr" title="concept-ltr">ltr</a>'.</p>

   </dd>

   <dt><dfn id="selector-rtl" title="selector-rtl"><code>:rtl</code></dfn></dt>

   <dd>

    <p>The <code title="selector-rtl"><a href="#selector-rtl">:rtl</a></code> pseudo-class must
    match all elements whose <a href="elements.html#the-directionality" title="the
    directionality">directionality</a> is '<a href="elements.html#concept-rtl" title="concept-rtl">rtl</a>'.</p>

   </dd>

  </dl><p class="note">Another section of this specification defines the
  <i><a href="history.html#target-element">target element</a></i> used with the <code title="selector-target">:target</code> pseudo-class.</p>

  <p class="note">This specification does not define when an element
  matches the <code title="selector-hover">:hover</code>, <code title="selector-focus">:focus</code>, or <code title="selector-lang()">:lang()</code> dynamic pseudo-classes, as
  those are all defined in sufficient detail in a language-agnostic
  fashion in the Selectors specification. <a href="references.html#refsSELECTORS">[SELECTORS]</a></p>

  </div></body></html>