Check in some notes on :drop-zone.

Author: fantasai

selectors4/Overview.src.html

@@ -845,7 +845,6 @@ <h3 id=type-selectors>
    <pre>h1</pre>
   </div>
 
-
 <h4 id=typenmsp>
 Type selectors and namespaces</h4>
 
@@ -1522,6 +1521,9 @@ <h3 id=target-pseudo>
 <h3 id=scope-pseudo>
 The contextual reference element pseudo-class '':scope''</h3>
 
+  <p class="issue">Should this be renamed to <code>:context</code>, since
+  it's referencing a <em>context</em>ual reference element?</p>
+
   <p>The <code>:scope</code> pseudo-class represents any element that is in
   the <i>contextual reference element set</i>. If no contextual reference
   element set is given, <code>:scope</code> is equivalent to <code>:root</code>.
@@ -1581,6 +1583,31 @@ <h3 id="hover-pseudo">
 
   <p>The <code>:hover</code> pseudo-class can apply to any pseudo-element.
 
+<!--
+<h3 id="hover-pseudo">
+The pointer hover pseudo-class '':drop-zone''</h3>
+
+  <p>The <code>:drop-zone</code> pseudo-class applies while the user
+    is &rdquo;dragging&ldquo; or otherwise conceptually carrying an item
+    for which the element is a valid drop target.
+    User agents not that do not support <a
+    href="http://www.w3.org/TR/CSS21/media.html#interactive-media-group">interactive
+    media</a> do not have to support this pseudo-class. Some conforming
+    user agents that support <a
+    href="http://www.w3.org/TR/CSS21/media.html#interactive-media-group">interactive
+    media</a> may not be able to support this pseudo-class (e.g., a
+    keyboard-only device that has no concept of dragging).
+
+  <div class="example">
+    <p>This pseudo-class could be used, for example, to highlight all the
+    valid drop targets for the item being dragged.
+    <pre>:drop-zone { box-shadow: 0 0 5px yellow; }</pre>
+    <p>It can also be combined with <code>:drag-over</code> to designate the
+    drop-zone that will receive the dragged item when dropped.
+    <pre>:drop-zone:drag-over { outline: solid red; }</pre>
+  </div>
+-->
+
 <h3 id="active-pseudo">
 The activation pseudo-class '':active''</h3>