--- a/ttml10-sdp-us/Overview.html	Wed Nov 28 23:59:09 2012 -0700
+++ b/ttml10-sdp-us/Overview.html	Thu Nov 29 00:06:39 2012 -0700
@@ -933,6 +933,8 @@
 media object [<cite><a class="bibref" href="#bib-TTML10SE">TTML10SE</a></cite>], Section 2.2.</div></div>
 <div><div class="numbered constraint" title="R0022">A presentation processor <em class="rfc2119" title="must">must</em> fix the root container extent so that it corresponds with the extent of the related
 media object [<cite><a class="bibref" href="#bib-TTML10SE">TTML10SE</a></cite>], Section 2.2.</div></div>
+<div class="note"><div class="note-title"><span>Note</span></div><div class="">In the context of this document, the related media object [<cite><a class="bibref" href="#bib-TTML10SE">TTML10SE</a></cite>] is assumed to be video media, and, therefore, have an
+associated origin and extent on some display device.</div></div>
 </section>
 <section class="informative" id="examples">
 <h4><span class="secno">7.4.3 </span>Examples</h4><p><em>This section is non-normative.</em></p>

--- a/ttml10-sdp-us/Overview.src.html	Wed Nov 28 23:59:09 2012 -0700
+++ b/ttml10-sdp-us/Overview.src.html	Thu Nov 29 00:06:39 2012 -0700
@@ -736,6 +736,8 @@
 media object [[TTML10SE]], Section 2.2.</div>
 <div data-transform='constraint'>A presentation processor MUST fix the root container extent so that it corresponds with the extent of the related
 media object [[TTML10SE]], Section 2.2.</div>
+<div class='note'>In the context of this document, the related media object [[TTML10SE]] is assumed to be video media, and, therefore, have an
+associated origin and extent on some display device.</div>
 </section>
 <section class='informative'>
 <h4>Examples</h4>