title: Is role="tooltip" important?
body: <ol>
  <li>Most Screen readers read the custom tooltip information by default. role="tooltip" does not seem to do anything additional, like it doesnt inform user that its tooltip. Why do we need to use role="tooltip" for the tooltip container? Any specific purpose?</li>
  <li>Tooltip information not read by NVDA in IE11. Any hacks to fix?</li>
  </ol>
  
  <p>Here's my code:</p>
  
  <pre><code>&lt;div class="ttipcontainer"&gt;
    &lt;button title="" class="co_tooltipElement" id="newButton05-2" aria-describedby="coid_accessibleTooltip_1"&gt; Recent Searches &lt;/button&gt; 
    &lt;span tabindex="-1" class="co_accessibilityLabel" id="coid_accessibleTooltip_1" aria-hidden="true" role="tooltip"&gt;Shows information of your recent searches&lt;/span&gt;
  &lt;/div&gt;
  </code></pre>