[ttml2] define ruby fallback semantics rather than leave as implementation dependent
--- a/ttml2/spec/ttml2.xml Tue Oct 21 13:15:37 2014 -0700
+++ b/ttml2/spec/ttml2.xml Mon Oct 27 11:32:40 2014 -0700
@@ -7100,7 +7100,7 @@
<td>Ruby Fallback Delimiter</td>
<td><code>delimiter</code></td>
<td><code>rp</code></td>
-<td><code>none</code></td>
+<td><code>none</code> | <code>inline</code></td>
</tr>
</tbody>
</table>
@@ -7160,7 +7160,11 @@
</ulist>
<p>A validating processor must treat a violation of any of the above constraints as an error.
For the purpose of presentation processing, the violation of any of these constraints should result in fallback (inline)
-presentation of ruby text annotations, where fallback annotation presentation is considered to be implementation dependent.</p>
+presentation of ruby text annotations.</p>
+<p>When performing normal presentation processing of ruby text annotations, delimiter content must not generate any
+inline areas. When performing fallback presentation of ruby, both delimiter and non-delimiter ruby (base and text) content
+must generate normal inline areas.</p>
+<p>If a presentation processor does not support ruby presentation, then it must perform fallback ruby presentaton.</p>
<note role="elaboration">
<p>The above listed constraints are intended to be interpreted as specifying the following nesting model:</p>
<eg xml:space="preserve">