Clarify what happens when a border-image applies or doesn't apply. <http://lists.w3.org/Archives/Public/www-style/2012Mar/0109.html> LC issue 21

Author: fantasai

css3-background/Overview.src.html

@@ -2277,9 +2277,10 @@ <h3 id="the-border-image-source">Image Source: the 'border-image-source' propert
 
 <p>Specifies an image to use instead of the border styles given by the
 'border-style' properties and as an additional background layer for the
-element. If the value is <dfn title="''none''!!'border-image-source'
-value">''none''</dfn> or if the image cannot be displayed,
-the border styles will be used.
+element. If the value is ''none'' or if the image cannot be displayed
+(or the property doesn't apply), the border styles will be used;
+otherwise the element's borders are not drawn and the border image is
+drawn as described in the sections below.
 
 <h3 id="the-border-image-slice">Image Slicing: the 'border-image-slice' property</h3>