prohibit aria-roledescription from role=generic (#1142)

index.html

@@ -3072,6 +3072,7 @@ <h2>Definition of Roles</h2>
 							<ul>
 								<li><pref>aria-label</pref></li>
 								<li><pref>aria-labelledby</pref></li>
+								<li><pref>aria-roledescription</pref></li>
 							</ul>
 						</td>
 					</tr>
@@ -11653,6 +11654,7 @@ <h2>Definitions of States and Properties (all aria-* attributes)</h2>
 				<p>User agents MUST NOT expose the <code>aria-roledescription</code> property if any of the following conditions exist:</p>
 				<ol>
 					<li>The element to which <code>aria-roledescription</code> is applied does not have a valid WAI-ARIA role or does not have an implicit WAI-ARIA role semantic.</li>
+					<li>The element to which <code>aria-roledescription</code> is applied has an explicit or implicit WAI-ARIA role where <code>aria-roledescription</code> is <a href="#prohibitedattributes">prohibited</a>.</li>
 					<li>The value of <code>aria-roledescription</code> is empty or contains only whitespace characters.</li>
 				</ol>
 				<p><a>Assistive technologies</a> SHOULD use the value of <code>aria-roledescription</code> when presenting the role of an element, but SHOULD NOT change other functionality based on the role of an element that has a value for <code>aria-roledescription</code>. For example, an assistive technology that provides functions for navigating to the next <rref>region</rref> or <rref>button</rref> SHOULD allow those functions to navigate to regions and buttons that have an <code>aria-roledescription</code>.</p>