Update names-and-descriptions-practice.html

My suggested wording approach, based on w3c#3211

content/practices/names-and-descriptions/names-and-descriptions-practice.html

@@ -1360,11 +1360,11 @@ <h2><span id="naming_role_guidance_heading">Accessible Name Guidance by Role</sp
               <td>
                 <a href="#tablist" class="role-reference"><code>tablist</code></a>
               </td>
-              <td>Recommended</td>
+              <td>Required **only if** a visible label is present</td>
               <td>
                 <ul>
                   <li>Helps screen reader users understand the context and purpose of the tablist.</li>
-                  <li>Use <code>aria-labelledby</code> if a visible label is present, otherwise use <code>aria-label</code>.</li>
+                  <li>Use <code>aria-labelledby</code> if a visible label is present, otherwise optionally use <code>aria-label</code>.</li>
                   <li>See the <a href="../../patterns/carousel/carousel-pattern.html">Carousel Pattern</a> and <a href="../../patterns/tabs/tabs-pattern.html">Tabs Pattern</a>.</li>
                 </ul>
               </td>