Move lightbox example into list of failures

understanding/22/focus-not-obscured-enhanced.html

@@ -23,7 +23,7 @@ <h2>Intent of Focus Not Obscured (Enhanced)</h2>
   <p>The intent of this Success Criterion is to ensure that the item receiving keyboard focus is always visible in the user's viewport. For sighted people who rely on a keyboard (or on a device that operates through the keyboard interface, such as a switch or voice input), knowing the current point of focus is critical. The component with focus signals the interaction point on the page. Where users cannot see the item with focus, they may not know how to proceed, or may even think the system has become unresponsive.</p>
   <p>Typical types of content that can overlap focused items are sticky footers, sticky headers, and non-modal dialogs. As a user tabs through the page, these layers of content can obscure the item receiving focus, along with its focus indicator.</p>
   <p>A notification implemented as sticky content, such as a cookie banner, will fail this Success Criterion if it partially obscures a component receiving focus. Ways of passing include making the banner modal so the user has to dismiss the banner before navigating through the page, or using <a href="https://www.w3.org/TR/css-scroll-snap/#propdef-scroll-padding">scroll padding</a> so the banner does not overlap other content. Notifications that do not require user action could also meet this criterion by closing on loss of focus.</p>
-  <p>Another form of obscuring can occur where light boxes or other semi-opaque effects overlap the item with focus. While less than 100 percent opacity is causing the component to be <q>partially hidden</q> and such semi-opaque overlaps may cause a failure of <a href="https://www.w3.org/WAI/WCAG22/Understanding/focus-appearance.html">2.4.11 Focus Appearance</a>, such effects are not in scope for this criterion. When a focus indicator can be covered by a semi-opaque component, the ability of the focus indicator to pass 2.4.11 should be evaluated (and pass) while the focus indicator is under the semi-opaque component. The intention in both situations is that the component receiving focus should never be obscured to the point a user cannot tell which item has focus.</p>
+  <p>Another form of obscuring can occur where light boxes or other semi-opaque effects overlap the item with focus. While less than 100 percent opacity is not <q>entirely hidden</q>, it is causing the component to be <q>partially hidden</q> and a failure of this Success Criterion.  Such semi-opaque overlaps may <em>also</em> cause a failure of <a href="../understanding/focus-appearance.html">2.4.11 Focus Appearance</a>.</p>
 </section>
 <section id="benefits">
   <h2>Benefits of Focus Not Obscured (Enhanced)</h2>
@@ -59,6 +59,7 @@ <h3>Additional Techniques (Advisory)</h3>
     <h3>Failures</h3>
     <ul>
       <li>An interaction that causes content to appear over the component with keyboard focus, visually covering part of the focus indicator. This behavior might be encountered with advertising or promotional material meant to provide more information about a product as the user navigates through a catalogue.</li>
+      <li>A light box or other semi-opaque effect that overlaps the focus indicator.  The obscuring may triggered by a component receiving focus or from other interation, but is a failure regardless.</li>
       <li>A page has a sticky footer (attached to the bottom of the viewport). When tabbing down the page, a focused item is partially hidden by the footer because content in the viewport scrolls without sufficient <a href="https://www.w3.org/TR/css-scroll-snap/#propdef-scroll-padding" rel="nofollow">scroll padding</a>.</li>
     </ul>
   </section>