diff --git a/index.html b/index.html
index cd2235c7..ae2353af 100644
--- a/index.html
+++ b/index.html
@@ -1260,7 +1260,11 @@ <h3>HTML Element Role Mappings</h3>
               <td class="uia"><div class="general">Use WAI-ARIA mapping</div></td>
               <td class="atk"><div class="general">Use WAI-ARIA mapping</div></td>
               <td class="ax"><div class="general">Use WAI-ARIA mapping</div></td>
-              <td class="comments"></td>
+              <td class="comments">
+                If an `hgroup` contains multiple heading elements, then the heading element with the highest priority level 
+                MUST be treated as the sole heading of the `hgroup`. All other heading elements MUST instead be exposed as if they
+                were `p` elements.
+              </td>
             </tr>
             <tr tabindex="-1" id="el-hr">
               <th>