[css-shapes] add two clauses to serialization

Author: astearns

css-shapes/Overview.html

@@ -63,7 +63,7 @@
 </p>
   <h1 class="p-name no-ref" id=title>CSS Shapes Module Level 1</h1>
   <h2 class="no-num no-toc no-ref heading settled heading" id=subtitle><span class=content>Editor’s Draft,
-    <span class=dt-updated><span class=value-title title=20140116>16 January 2014</span></span></span></h2>
+    <span class=dt-updated><span class=value-title title=20140121>21 January 2014</span></span></span></h2>
   <div data-fill-with=spec-metadata><dl><dt>This version:<dd><a class=u-url href=http://dev.w3.org/csswg/css-shapes/>http://dev.w3.org/csswg/css-shapes/</a><dt>Latest version:<dd><a href=http://www.w3.org/TR/css-shapes/>http://www.w3.org/TR/css-shapes/</a><dt>Editor’s Draft:<dd><a href=http://dev.w3.org/csswg/css-shapes/>http://dev.w3.org/csswg/css-shapes/</a>
     <dt>Feedback:</dt>
         <dd><a href="mailto:www-style@w3.org?subject=%5Bcss-shapes%5D%20feedback">www-style@w3.org</a>
@@ -601,7 +601,14 @@ <h3 class="heading settled heading" data-level=3.2 id=basic-shape-computed-value
 <h3 class="heading settled heading" data-level=3.3 id=basic-shape-serialization><span class=secno>3.3 </span><span class=content>
 Serialization of Basic Shapes</span><a class=self-link href=#basic-shape-serialization></a></h3>
 
-<p>	To serialize the <a class="production css-code" data-link-type=type href=#typedef-basic-shape title="<basic-shape>">&lt;basic-shape&gt;</a> functions, serialize as per their individual grammars, in the order the grammars are written in, omitting components when possible without changing the meaning, joining space-separated tokens with a single space, and following each serialized comma with a single space. 
+<p>	To serialize the <a class="production css-code" data-link-type=type href=#typedef-basic-shape title="<basic-shape>">&lt;basic-shape&gt;</a> functions, 
+	serialize as per their individual grammars, 
+	in the order the grammars are written in, 
+	avoiding calc() expressions where possible, 
+	using keywords where possible, 
+	omitting components when possible without changing the meaning, 
+	joining space-separated tokens with a single space, 
+	and following each serialized comma with a single space. 
 
 <h3 class="heading settled heading" data-level=3.4 id=basic-shape-interpolation><span class=secno>3.4 </span><span class=content>
 Interpolation of Basic Shapes</span><a class=self-link href=#basic-shape-interpolation></a></h3>

css-shapes/Overview.src.html

@@ -480,7 +480,14 @@ <h3 id='basic-shape-computed-values'>
 <h3 id='basic-shape-serialization'>
 Serialization of Basic Shapes</h3>
 
-	To serialize the <<basic-shape>> functions, serialize as per their individual grammars, in the order the grammars are written in, omitting components when possible without changing the meaning, joining space-separated tokens with a single space, and following each serialized comma with a single space. 
+	To serialize the <<basic-shape>> functions, 
+	serialize as per their individual grammars, 
+	in the order the grammars are written in, 
+	avoiding calc() expressions where possible, 
+	using keywords where possible, 
+	omitting components when possible without changing the meaning, 
+	joining space-separated tokens with a single space, 
+	and following each serialized comma with a single space. 
 
 <h3 id='basic-shape-interpolation'>
 Interpolation of Basic Shapes</h3>