[css-sizing-4] Rephrase the note to make more sense and state more usefully.

Author: tabatkins

css-sizing-4/Overview.bs

@@ -129,6 +129,16 @@ New Sizing Values: the ''stretch'', ''fit-content'', and ''contain'' keywords</h
 			applies [=stretch-fit sizing=].
 	</dl>
 
+<!--
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+ ██   ██  ██       ██     ██ ██       ██          ██            ██     ██  ██   ██     ██     ██  ██     ██
+██     ██  ██████  ████████  ██████   ██          ██    ███████ ████████  ██     ██    ██     ██  ██     ██
+█████████       ██ ██        ██       ██          ██            ██   ██   █████████    ██     ██  ██     ██
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+-->
+
 <h2 id="ratios">
 Aspect Ratios</h2>
 
@@ -210,14 +220,11 @@ Intrinsic Aspect Ratios: the 'aspect-ratio' property</h3>
 	The opposite axis (on which the [=ratio-dependent axis=] size depends)
 	is the <dfn export>ratio-determining axis</dfn>.
 
-	Note: If a box has both a 'width' and a 'height'
-	that are not <a lt="automatic size">automatic</a>
-	(or, in the case of a <a>flex item</a>,
-	both a ''flex-basis/content'' flex basis and
-	a non-<a lt="automatic size">automatic</a> preferred <a>cross size</a>),
-	then the <a>preferred aspect ratio</a> has no effect:
-	at least one of these sizes must be ''width/auto'' (/''flex-basis/content'')
-	for the <a>preferred aspect ratio</a> to have an impact on sizing.
+	Note: A [=preferred aspect ratio=]
+	only ever has an effect if at least one of the box's sizes
+	is [=automatic size|automatic=].
+	If neither 'width' nor 'height' is an [=automatic size=],
+	it can have no effect on its [=preferred sizes=].
 
 	For the purpose of margin collapsing ([[css2/box#collapsing-margins]]),
 	if the [=block axis=] is the [=ratio-dependent axis=],