diff --git a/spec/ttml2.xml b/spec/ttml2.xml
index 48bc99878..5f9c56a37 100644
--- a/spec/ttml2.xml
+++ b/spec/ttml2.xml
@@ -2099,8 +2099,12 @@ declared to apply to the <loc href="#terms-document-instance">document instance<
 <note role="clarification">
 <p>The phrase <emph>mandatory semantics</emph> refers to all explicit use of the conformance
 key phrases <phrase role ="strong">must</phrase> and <phrase role="strong">must not</phrase> as well as any
-declarative statement that can be reasonably inferred from such key phrases. For example, these
-mandatory semantics include support for all features marked as mandatory in <specref ref="feature-support"/>.</p>
+declarative statement that can be reasonably inferred from such key phrases.</p>
+</note>
+<note role="clarification">
+<p>Support for the <emph>mandatory semantics</emph> of a <loc href="#terms-feature">feature</loc> or
+<loc href="#terms-extension">extension</loc> applies only when the <loc href="#terms-feature">feature</loc> or
+<loc href="#terms-extension">extension</loc> is supported by a TTML <loc href="#terms-content-processor">content processor</loc>.</p>
 </note>
 </item>
 <item>
@@ -2110,8 +2114,7 @@ then it does so in a manner consistent with the defined semantics.</p>
 <p>The phrase <emph>optional semantics</emph> refers to all explicit use of the conformance
 key phrases <phrase role ="strong">should</phrase>, <phrase role="strong">should not</phrase>,
 <phrase role ="strong">may</phrase>, and <phrase role="strong">may not</phrase>,
-as well as any declarative statement that can be reasonably inferred from such key phrases. For example, these
-optional semantics include support for all features marked as optional in <specref ref="feature-support"/>.</p>
+as well as any declarative statement that can be reasonably inferred from such key phrases.</p>
 </note>
 </item>
 </olist>
@@ -19052,8 +19055,9 @@ is defined by <specref ref="conformance-content"/>.</p>
 <p><emph>This appendix is normative.</emph></p>
 <p>This appendix specifies (1) a set of feature designations, each of which
 labels one or more syntactic and/or semantic features defined by this
-specification, and (2) for each designated feature, whether the feature is mandatory
-or optional for a transformation or <loc href="#terms-presentation-processor">presentation processor</loc>.</p>
+specification, and (2) for each designated feature, whether the feature is mandatory or optional for a
+TTML <loc href="#terms-content-processor">content processor</loc> that complies with the requirements of
+<specref ref="conformance-transformation-processor"/> or <specref ref="conformance-presentation-processor"/>.</p>
 <note>
 <p>A TTML processor is said to <emph>implement the transformation semantics</emph> or
 <emph>implement the presentation semantics</emph> of feature designation <emph>F</emph>
@@ -22203,7 +22207,8 @@ enumerates every defined feature designation (expressed without the TT
 Feature Namespace), and, for each designated feature, specifies
 (1) the version of TTML in which the feature designation is first defined, and (2)
 whether the designated feature must be implemented, i.e., is mandatory (M), or may be implemented, i.e.,
-is optional (O), for transformation and <loc href="#terms-presentation-processor">presentation processor</loc>s.</p>
+is optional (O), for a TTML <loc href="#terms-content-processor">content processor</loc> that complies with the requirements of
+<specref ref="conformance-transformation-processor"/> or <specref ref="conformance-presentation-processor"/>.</p>
 <note role="clarification">
   <p>In some cases, a new feature designation is defined in this (or a later) version of this specification that wasn't previously defined, and yet
   the underlying functional feature so designated was previously defined by an earlier version. For example, the <code>#padding-region</code>
@@ -23650,7 +23655,8 @@ is optional (O), for transformation and <loc href="#terms-presentation-processor
 </table>
 <p>For the sake of convenience, the following table,
 <specref ref="feature-transformation-mandatory-table"/>, enumerates all
-mandatory features for a TTML <loc href="#terms-transformation-processor">transformation processor</loc>, providing additional
+mandatory features for a TTML <loc href="#terms-content-processor">content processor</loc> that complies with the requirements of
+<specref ref="conformance-transformation-processor"/>, providing additional
 comments to summarize the context of usage or the nature of the feature.
 The <loc href="#terms-profile-definition-document">profile definition document</loc> that defines the corresponding
 TTML Transformation Profile is specified in
@@ -23742,7 +23748,8 @@ TTML Transformation Profile is specified in
 </table>
 <p>For the sake of convenience, the following table,
 <specref ref="feature-presentation-mandatory-table"/>, enumerates all
-mandatory features for a TTML <loc href="#terms-presentation-processor">presentation processor</loc>, providing additional
+mandatory features for a TTML <loc href="#terms-content-processor">content processor</loc> that complies with the requirements of
+<specref ref="conformance-presentation-processor"/>, providing additional
 comments to summarize the context of usage or the nature of the feature.
 The <loc href="#terms-profile-definition-document">profile definition document</loc> that defines the corresponding
 TTML Presentation Profile is specified in