Revision 720677 of tabindex

<p class="note">{{HTMLSidebar("Global_attributes")}}</p>
<p>The <strong>tabindex</strong> <a href="/en-US/docs/Web/HTML/Global_attributes">global attribute</a> is an integer indicating if the element can take input focus (is <em>focusable</em>), if it should participate to sequential keyboard navigation, and if so, at what position. It can takes several values:</p>
<ul>
 <li>a <em>negative value</em> means that the element should be focusable, but should not be reachable via sequential keyboard navigation;</li>
 <li><code>0</code> means that the element should be focusable and reachable via sequential keyboard navigation, but its relative order is defined by the platform convention;</li>
 <li>a <span style="font-style: italic;">positive</span><em> value</em> which means should be focusable and reachable via sequential keyboard navigation; its relative order is defined by the value of the attribute: the sequential follow the increasing number of the <strong>tabindex</strong>. If several elements share the same tabindex, their relative order follows their relative position in the document).</li>
</ul>
<p>An element with a <code>0</code> value, an invalid value, or no <strong>tabindex</strong> value should be placed after elements with a positive <strong>tabindex</strong> in the sequential keyboard navigation order.</p>
<p>You can consult <a href="/en/Focus_management_in_HTML" title="en/Focus management in HTML">this article</a> to see a comprehensive explanation of focus management.</p>
<h2 id="Specifications">Specifications</h2>
<table class="standard-table">
 <tbody>
  <tr>
   <th scope="col">Specification</th>
   <th scope="col">Status</th>
   <th scope="col">Comment</th>
  </tr>
  <tr>
   <td>{{SpecName('HTML WHATWG', "editing.html#attr-tabindex", "tabindex")}}</td>
   <td>{{Spec2('HTML WHATWG')}}</td>
   <td>No change from latest snapshot, {{SpecName('HTML5.1')}}</td>
  </tr>
  <tr>
   <td>{{SpecName('HTML5.1', "editing.html#attr-tabindex", "tabindex")}}</td>
   <td>{{Spec2('HTML5.1')}}</td>
   <td>Snapshot of {{SpecName('HTML WHATWG')}}, no change from {{SpecName('HTML5 W3C')}}</td>
  </tr>
  <tr>
   <td>{{SpecName('HTML5 W3C', "editing.html#attr-tabindex", "tabindex")}}</td>
   <td>{{Spec2('HTML5 W3C')}}</td>
   <td>Snapshot of {{SpecName('HTML WHATWG')}}. From {{SpecName("HTML4.01")}}, the attribute is now supported on all elements (global attributes).</td>
  </tr>
  <tr>
   <td>{{SpecName('HTML4.01', 'interact/forms.html#adef-tabindex', 'tabindex')}}</td>
   <td>{{Spec2('HTML4.01')}}</td>
   <td>Only supported on {{HTMLElement("a")}}, {{HTMLElement("area")}}, {{HTMLElement("button")}}, {{HTMLElement("object")}}, {{HTMLElement("select")}}, and {{HTMLElement("textarea")}}.</td>
  </tr>
 </tbody>
</table>
<h2 id="Browser_compatibility">Browser compatibility</h2>
<p>{{ CompatibilityTable() }}</p>
<div id="compat-desktop">
 <table class="compat-table">
  <tbody>
   <tr>
    <th>Feature</th>
    <th>Chrome</th>
    <th>Firefox (Gecko)</th>
    <th>Internet Explorer</th>
    <th>Opera</th>
    <th>Safari</th>
   </tr>
   <tr>
    <td>Basic support</td>
    <td>{{ CompatVersionUnknown() }}</td>
    <td>{{ CompatVersionUnknown }}</td>
    <td>{{ CompatVersionUnknown() }}</td>
    <td>{{ CompatVersionUnknown() }}</td>
    <td>{{ CompatVersionUnknown() }}</td>
   </tr>
  </tbody>
 </table>
</div>
<div id="compat-mobile">
 <table class="compat-table">
  <tbody>
   <tr>
    <th>Feature</th>
    <th>Android</th>
    <th>Chrome for Android</th>
    <th>Firefox Mobile (Gecko)</th>
    <th>IE Mobile</th>
    <th>Opera Mobile</th>
    <th>Safari Mobile</th>
   </tr>
   <tr>
    <td>Basic support</td>
    <td>{{ CompatVersionUnknown() }}</td>
    <td>{{ CompatVersionUnknown() }}</td>
    <td>{{ CompatVersionUnknown }}</td>
    <td>{{ CompatVersionUnknown() }}</td>
    <td>{{ CompatVersionUnknown() }}</td>
    <td>{{ CompatVersionUnknown() }}</td>
   </tr>
  </tbody>
 </table>
</div>
<h2 id="See_also">See also</h2>
<ul>
 <li>All <a href="/en-US/docs/Web/HTML/Global_attributes">global attributes</a>.</li>
</ul>