--- a/ttml10/spec/ttaf1-dfxp.xml	Mon Sep 24 11:06:16 2012 +0800
+++ b/ttml10/spec/ttaf1-dfxp.xml	Mon Sep 24 11:31:13 2012 +0800
@@ -28,6 +28,7 @@
 <!ENTITY le "&#x2264;">
 <!ENTITY ge "&#x2265;">
 <!ENTITY plusmn "&#x00B1;">
+<!ENTITY thinsp "&#x2009;">
 <!ENTITY dfxp-ex1 SYSTEM "./examples/ex1.xml.esc">
 <!ENTITY dfxp-ex1-x-0 SYSTEM "./examples/ex1-x-0.xml.esc">
 <!ENTITY dfxp-ex1-p-0 SYSTEM "./examples/ex1-p-0.xml.esc">
@@ -7194,10 +7195,10 @@
 each time coordinate, some element becomes temporally active or inactive,
 then, at each such time coordinate, a document
 instance is mapped from its original, source
-form, <emph>DOC<sub>source</sub></emph>, 
+form, <emph>DOC<sub>source</sub></emph>&thinsp;, 
 to an intermediate
 synchronic document form,
-<emph>DOC<sub>inter</sub></emph>, as follows:</p>
+<emph>DOC<sub>inter</sub></emph>&thinsp;, as follows:</p>
 <olist>
 <item>
 <p>for each temporally active region <emph>R</emph>, replicate the
@@ -7221,6 +7222,14 @@
 longer semantically relevant;</p>
 </item>
 </olist>
+<note role="elaboration">
+<p>In this section, the term <emph>prune</emph>, when used in reference to
+an element, means that the element is to be removed from its parent's children,
+which, in turn, implies that the descendants of the pruned element will no longer
+be descendants of the element's parent. When <emph>prune</emph> is used in
+reference to an attribute, it means that attribute is to be removed from its
+associated (owning) element node.</p>
+</note>
 <p>A content element is associated with a region according
 to the following ordered rules, where the first rule satisfied
 is used and remaining rules are skipped:</p>