[css-values-4] Make it clear that all the URL stuff applies to both url functions.

Author: tabatkins

css-values-4/Overview.bs

@@ -822,12 +822,12 @@ Quoted Strings: the <<string>> type</h3>
 <h3 id="urls">
 Resource Locators: the <<url>> type</h3>
 
-	The <<url>> type
+	The <<url>> type,
+	written with the <dfn>url()</dfn> and <dfn>src()</dfn> functions,
 	represents a <l spec=url>[=/URL=]</l>,
 	which is a pointer to a resource.
 
-	Typically, a <<url>> is written with the <dfn>url()</dfn>
-	or <dfn>src()</dfn> <a>functional notations</a>:
+	The syntax of <<url>> is:
 
 	<pre class="prod">
 		<dfn id="url-value">&lt;url></dfn> = url( <<string>> <<url-modifier>>* ) |
@@ -951,11 +951,11 @@ Fragment URLs</h5>
 	To work around some common eccentricities in browser URL handling,
 	CSS has special behavior for fragment-only urls.
 
-	If a ''url()''’s value starts with a U+0023 NUMBER SIGN (<code>#</code>) character,
+	If a <<url>>'s value starts with a U+0023 NUMBER SIGN (<code>#</code>) character,
 	parse it as per normal for URLs,
-	but additionally set the <dfn export for="url()">local url flag</dfn> of the ''url()''.
+	but additionally set the <dfn export for="url()">local url flag</dfn> of the <<url>>.
 
-	When matching a ''url()'' with the <a>local url flag</a> set,
+	When matching a <<url>> with the <a>local url flag</a> set,
 	ignore everything but the URL's fragment,
 	and resolve that fragment against the [=node tree=]
 	of the stylesheet's [=CSSStyleSheet/owner node=].
@@ -1007,12 +1007,13 @@ Fragment URLs</h5>
 <h4 id="url-empty">
 Empty URLs</h4>
 
-	If the value of the ''url()'' is the empty string
+	If the value of the <<url>> is the empty string
 	(like ''url("")'' or ''url()''),
 	the url must resolve to an invalid resource
 	(similar to what the url ''about:invalid'' does).
 
-	Its computed value is ''url("")'',
+	Its computed value is ''url("")'' or ''src("")'',
+	whichever was specified,
 	and it must serialize as such.
 
 	<wpt>
@@ -1030,7 +1031,7 @@ Empty URLs</h4>
 <h4 id='url-modifiers'>
 URL Modifiers</h4>
 
-	The ''url()'' function supports specifying additional <dfn>&lt;url-modifier></dfn>s,
+	<<url>>s support specifying additional <dfn>&lt;url-modifier></dfn>s,
 	which change the meaning or the interpretation of the URL somehow.
 	A <<url-modifier>> is either an <<ident>> or a <a>functional notation</a>.