Copy over some of the text from <http://www.w3.org/TR/CSS21/conform.html#intrinsic> into the definition of intrinsic dimensions.

--HG--
extra : rebase_source : 8f5e11c7bddbaa74600aa4a0cec848926e058adc

Author: tabatkins

css3-images/Overview.html

@@ -1660,7 +1660,8 @@ <h3 id=sizing-terms><span class=secno>5.1. </span> Object-Sizing
      between the width and height), each of which may or may not exist for a
      given object. These intrinsic dimensions represent a preferred or
      natural size of the object itself; that is, they are not a function of
-     the context in which the object is used.</p>
+     the context in which the object is used. CSS does not define how the
+     intrinsic dimensions are found in general.</p>
 
     <p>Raster images are an example of an object with all three intrinsic
      dimensions. SVG images designed to scale might have only an intrinsic

css3-images/Overview.src.html

@@ -1053,7 +1053,7 @@ <h3 id="sizing-terms">
 	<dl>
 		<dt><dfn>intrinsic dimensions</dfn></dt>
 		<dd>
-			<p>The term intrinsic dimensions refers to the set of the <dfn>intrinsic height</dfn>, <dfn>intrinsic width</dfn>, and <dfn>intrinsic aspect ratio</dfn> (the ratio between the width and height), each of which may or may not exist for a given object. These intrinsic dimensions represent a preferred or natural size of the object itself; that is, they are not a function of the context in which the object is used.</p>
+			<p>The term intrinsic dimensions refers to the set of the <dfn>intrinsic height</dfn>, <dfn>intrinsic width</dfn>, and <dfn>intrinsic aspect ratio</dfn> (the ratio between the width and height), each of which may or may not exist for a given object. These intrinsic dimensions represent a preferred or natural size of the object itself; that is, they are not a function of the context in which the object is used.  CSS does not define how the intrinsic dimensions are found in general.</p>
 
 			<p>Raster images are an example of an object with all three intrinsic dimensions.  SVG images designed to scale might have only an intrinsic aspect ratio; SVG images can also be created with only an intrinsic width or height.  CSS gradients, defined in this specification, are an example of an object with no intrinsic dimensions at all.  Another example of this is embedded documents, such as the <code>&lt;iframe></code> element in HTML.  An object cannot have only two intrinsic dimensions, as any two automatically define the third.</p>