title: ARIA role validation challenge
body: <p>With this code:</p>
  
  <pre class="lang-html prettyprint-override"><code>&lt;ul class="tabs-nav" role="tablist" &gt;
         &lt;li role="tab"&gt;&lt;a href="#newspane"  id="tab-newnews"&gt;Latest News&lt;/a&gt;&lt;/li&gt;
         &lt;li role="tab"&gt;&lt;a href="#presspane" id="tab-press"  &gt;Press Releases&lt;/a&gt;&lt;/li&gt;
  &lt;/ul&gt;
  
  &lt;div&gt;
       &lt;div id="pane-newnews" role="tabpanel" aria-labelledby="tab-newnews" aria-hidden="false"&gt;
          &lt;p&gt;Lorem&lt;/p&gt;          
       &lt;/div&gt;
  
       &lt;div id="pane-press" role="tabpanel" aria-labelledby="tab-press" aria-hidden="true"&gt;
           &lt;p&gt;Ipsem&lt;/p&gt;                     
       &lt;/div&gt;
   &lt;/div&gt;
  </code></pre>
  
  <p>I get this error on the <a href="http://validator.w3.org/" rel="nofollow">W3C Validator</a>:</p>
  
  <p><strong>"Bad value tablist for attribute role on element div"</strong></p>
  
  <p>I have turned over every rock in the documentation and find no reason this would not validate.  Can anyone explain what I am doing wrong?</p>
  
  <p>Thank you!</p>