[css-counter-styles-3] Add diff to changes list for speak-as clarification.

Author: fantasai

css-counter-styles-3/Overview.bs

@@ -1134,7 +1134,8 @@ Speech Synthesis: the '@counter-style/speak-as' descriptor</h3>
 	or possible but nonsensical when naively read out loud.
 	The '@counter-style/speak-as' descriptor describes how to synthesize the spoken form of a counter formatted with the given counter style.
 	Assistive technologies should use this spoken form when reading out the counter style,
-	and may use the 'speak-as' value to inform transformations to outputs other than speech.
+	and may use the '@counter-style/speak-as' value
+	to inform transformations to outputs other than speech.
 	Values have the following meanings:
 
 	<dl dfn-for="@counter-style/speak-as" dfn-type=value>
@@ -2649,10 +2650,21 @@ Changes since the December 2017 Candidate Recommendation</h3>
 		(<a href="https://github.com/w3c/csswg-drafts/issues/6200">Issue 6200</a>)
 	* Allowed UAs to override the font choice of predefined symbolic counter styles.
 		(<a href="https://github.com/w3c/csswg-drafts/issues/6201">Issue 6201</a>)
-	* Restricted special rendering of predefined symbolic counter styles to usage as a list marker via 'list-style-type'.
+	* Restricted special rendering of predefined symbolic counter styles
+		to usage as a list marker via 'list-style-type'.
 		(<a href="https://github.com/w3c/csswg-drafts/issues/6201">Issue 6201</a>)
 	* Clarified that 'speak-as' represents spoken output; it may be used for other AT.
 		(<a href="https://github.com/w3c/csswg-drafts/issues/6040">Issue 6040</a>)
+		<blockquote>
+			<p>A counter style can be constructed with a meaning that is obvious visually,
+			but impossible to meaningfully represent via a speech synthesizer or other non-visual means,
+			or possible but nonsensical when naively read out <ins>loud</ins>.
+			The '@counter-style/speak-as' descriptor describes how to synthesize
+			the spoken form of a counter formatted with the given counter style.
+			<ins>Assistive technologies should use this spoken form when reading out the counter style,
+			and may use the '@counter-style/speak-as' value
+			to inform transformations to outputs other than speech.</ins>
+		</blockquote>
 
 	A <a href="https://drafts.csswg.org/css-counter-styles-3/issues-cr-2017">Disposition of Comments</a> is available.