resolves #1058

index.html

@@ -13545,7 +13545,7 @@ <h2>Interface Mixin <dfn>AriaAttributes</dfn></h2>
 		</pre>
 		<section id="reflection" class="normative">
 			<h2>ARIA Attribute Reflection</h2>
-			<p>User agents MUST <a href="https://html.spec.whatwg.org/multipage/common-dom-interfaces.html#reflecting-content-attributes-in-idl-attributes">reflect</a> the following content attributes to each of the corresponding IDL attributes.</p>
+			<p>User agents MUST <a href="https://html.spec.whatwg.org/multipage/common-dom-interfaces.html#reflecting-content-attributes-in-idl-attributes">reflect</a> the following content attributes to each of the corresponding IDL attributes. When the ARIA content attribute definition includes a table enumerating the attribute's allowed values, that attribute is an enumerated attribute. When the values table notates one of the values as "(default)", that default value is the missing value default and invalid value default for the attribute.</p>
 			<table>
 				<tr><th>IDL Attribute</th><th>Reflected ARIA Content Attribute</th></tr>
 				<tr><td><dfn>ariaActiveDescendantElement</dfn></td><td><pref>aria-activedescendant</pref></td></tr>