[css-images-3] bikeshed fixups

Author: tabatkins

css-images-3/Overview.bs

@@ -12,7 +12,7 @@ Abstract: This module contains the features of CSS level 3 relating to the <<ima
 Issue Tracking: Tracker http://www.w3.org/Style/CSS/Tracker/products/27
 Previous Version: http://www.w3.org/TR/2012/CR-css3-images-20120417/
 Previous Version: http://www.w3.org/TR/2012/WD-css3-images-20120112/
-Ignored Terms: <offset>, background positioning area, border image area, <meetorslice>, <ending-shape>, Map
+Ignored Terms: <offset>, background positioning area, border image area, <meetorslice>, <ending-shape>, Map, center
 Link Defaults: css21 (property) display
 </pre>
 
@@ -676,7 +676,7 @@ Radial Gradients: the ''radial-gradient()'' notation {#radial-gradients}
 
 	The arguments are defined as follows:
 
-	<dl dfn-type=value dfn-for="radial-gradient() repeating-radial-gradient()">
+	<dl dfn-type=value dfn-for="radial-gradient(), repeating-radial-gradient()">
 		<dt><dfn><<position>></dfn>
 		<dd>
 			Determines the <dfn dfn>gradient center</dfn> of the gradient.
@@ -686,11 +686,11 @@ Radial Gradients: the ''radial-gradient()'' notation {#radial-gradients}
 			and is resolved using the center-point as the object area
 			and the <a>gradient box</a> as the positioning area.
 			If this argument is omitted,
-			it defaults to ''center''.
+			it defaults to ''<position>/center''.
 
 		<dt><dfn><<ending-shape>></dfn>
 		<dd>
-			Can be either ''circle'' or ''ellipse'';
+			Can be either <dfn value for="<ending-shape>">circle</dfn> or <dfn value for="<ending-shape>">ellipse</dfn>;
 			determines whether the gradient's <a>ending shape</a> is a circle or an ellipse, respectively.
 			If <<ending-shape>> is omitted,
 			the <a>ending shape</a> defaults to a circle