diff --git a/imsc1/spec/ttml-ww-profiles.html b/imsc1/spec/ttml-ww-profiles.html
index b6a2651d..dcf66f5f 100644
--- a/imsc1/spec/ttml-ww-profiles.html
+++ b/imsc1/spec/ttml-ww-profiles.html
@@ -978,7 +978,10 @@ <h4>ittp:activeArea</h4>
           property where a two percentage value position is used.</p>
         </div>
 
-        <p>The <a>Active Area</a> SHALL NOT extend outside the root container in any dimension.</p>
+        <div class='note'>
+          <p>The syntax of the <code>ittp:activeArea</code> parameter is such that the <a>Active Area</a> cannot extend outside the
+          root container in any dimension.</p>
+        </div>
 
         <p>The <code>ittp:activeArea</code> attribute is considered to be significant only when specified on the <code>tt</code>
         element.</p>