[css-flexbox] Tweak wording of note about spatial navigation. Fixes #1677.

Author: fantasai

css-flexbox/Overview.bs

@@ -1372,10 +1372,10 @@ Reordering and Accessibility</h4>
 	This section does not preclude respecting the 'order' property
 	when determining element ordering in such spatial navigation modes;
 	indeed it would need to be considered for such a feature to work.
-	However a UA that uses 'order' in determining sequential navigation,
-	but does not otherwise account for spatial relationships among elements
-	(as expressed by the various layout features of CSS including and not limited to flex layout),
-	is non-conforming.
+	But 'order' is not the only (or even the primary) CSS property
+	that would need to be considered for such a spatial navigation feature.
+	A well-implemented spatial navigation feature would need to consider
+	all the layout features of CSS that modify spatial relationships.
 
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@@ -3475,6 +3475,24 @@ Clarifications</h4>
 		<li>Made sure that <a>main size</a> and <a>cross size</a> are defined
 			for <a>flex containers</a> as well as for <a>flex items</a>.
 			(<a href="https://github.com/w3c/csswg-drafts/issues/981">Issue 981</a>)
+		<li>Tweaked final clarifying sentence of note about spatial navigation.
+			(<a href="https://github.com/w3c/csswg-drafts/issues/1677">Issue 1677</a>)
+			<blockquote>
+				<p class="note">
+					User agents, including browsers, accessible technology, and extensions,
+					may offer spatial navigation features.
+					This section does not preclude respecting the 'order' property
+					when determining element ordering in such spatial navigation modes;
+					indeed it would need to be considered for such a feature to work.
+					<del>However a UA that uses 'order' in determining sequential navigation,
+					but does not otherwise account for spatial relationships among elements
+					(as expressed by the various layout features of CSS including and not limited to flex layout),
+					is non-conforming.</del>
+					<ins>But 'order' is not the only (or even the primary) CSS property
+					that would need to be considered for such a spatial navigation feature.
+					A well-implemented spatial navigation feature would need to consider
+					all the layout features of CSS that modify spatial relationships.</ins>
+			</blockquote>
 	</ul>
 
 <h3 id="changes-20160301">