[css-pseudo-4] Define selection more generically, shift some text around. w3c#3425

Author: fantasai

css-pseudo-4/Overview.bs

@@ -424,17 +424,23 @@ Highlight Pseudo-elements</h2>
 Selecting Highlighted Content: the ''::selection'',  ''::inactive-selection'', ''::spelling-error'', and ''::grammar-error'' pseudo-elements</h3>
 
   The <dfn export lt="highlight pseudo-element">highlight pseudo-elements</dfn>
-  represent portions of a document that have been highlighted in some way.
-  They do not necessarily fit into the element tree,
-  and can arbitrarily cross element boundaries without honoring its nesting structure.
+  represent portions of a document that have been given a particular status
+  and are typically styled differently to indicate that status to the user.
+  For example,
+  selected portions of the document are typically highlighted
+  (given alternate background and foreground colors, or a color wash)
+  to indicate their selected status.
+  The following <a>highlight pseudo-elements</a> are defined:
 
   <dl export>
     <dt><dfn>::selection</dfn>
     <dt><dfn>::inactive-selection</dfn>
     <dd>
       The ''::selection'' and ''::inactive-selection'' pseudo-elements represent
-      the portion of a document that has been highlighted by the user.
-      This also applies, for example, to selected text within an editable text field.
+      the portion of a document that has been selected
+      as the target or object of some possible future user-agent operation(s).
+      They apply, for example, to selected text within an editable text field,
+      which would be copied by a copy operation or replaced by a paste operation.
 
       ''::selection'' applies to active selections,
       whereas ''::inactive-selection'' applies to inactive selections
@@ -451,6 +457,9 @@ Selecting Highlighted Content: the ''::selection'',  ''::inactive-selection'', '
       a portion of text that has been flagged by the user agent as grammatically incorrect.
   </dl>
 
+  The <a>highlight pseudo-elements</a>
+  do not necessarily fit into the element tree,
+  and can arbitrarily cross element boundaries without honoring its nesting structure.
 
     The following addition is made to the default UA stylesheet:
 	<pre><code class="lang-css">