Clarify note wording for presentation processor style support (#270)

index.html

@@ -2698,7 +2698,7 @@ <h3>Conformance of DAPT Processors</h3>
             for example, just rendering the text, event by event; or rendering the text of all the events
             all at once along a timeline; or one doing the audio mixing, would be considered
             a <a>presentation processor</a>. A <a>presentation processor</a> can also support additional rendering features
-            from TTML2, such as styles for DAPT documents that use that.</li>
+            that are not required by DAPT, for example those supporting visual styling attributes from [[TTML2]] or [[TTML-IMSC1.2]].</li>
           <li>A DAPT authoring tool, producing DAPT documents from scratch or from an other document,
             would be considered a <a>transformation processor</a>. It may also be considered as
             a <a>presentation processor</a> if it does any form of rendering of the text or the audio.</li>