diff --git a/source b/source
index ff41e74a468..1ae14b1f647 100644
--- a/source
+++ b/source
@@ -56864,7 +56864,7 @@ dictionary <dfn>RelatedEventInit</dfn> : <span>EventInit</span> {
 
   <ol>
 
-   <li><p>If for some reason <var>subject</var> is not a <span>control group owner</span>
+   <li><p>If for some reason <var>subject</var> is not a <span>control group owner object</span>
    at this point, or if it is <span>inert</span>, abort these steps.</p></li>
 
    <li>
@@ -71298,10 +71298,9 @@ END:VCARD</pre>
   container</span> essentially acts merely as a placeholder for its <span>nested browsing
   context</span>'s <span>active document</span>.</p>
 
-  <p>Each <span>focusable area</span> belongs to a <dfn>control group</dfn>. Each <span>control group</span> has
-  an <dfn data-x="control group owner">owner</dfn>. <span data-x="control group owner">Control group
-  owners</span> are <dfn data-x="control group owner object">control group owner objects</dfn>. The
-  following are <span data-x="control group owner object">control group owner objects</span>:</p>
+  <hr>
+
+  <p>The following create <dfn data-x="control group">control groups</dfn>:
 
   <ul class="brief">
 
@@ -71313,13 +71312,17 @@ END:VCARD</pre>
 
   </ul>
 
-  <p>Each <span>control group owner object</span> owns one <span>control group</span> (though that
-  group might be empty).</p>
+  <p>The corresponding <code>Document</code> object or <code>dialog</code> element is the created
+  <span>control group</span>'s <dfn data-x="control group owner object">owner object</dfn>. (There
+  is always a 1:1 mapping of <span data-x="control group">control groups</span> to <span
+  data-x="control group owner object">control group owner objects</span>.)</p>
 
-  <p>If the <span>DOM anchor</span> of a <span>focusable area</span> is a <span>control group owner
-  object</span>, then that <span>focusable area</span> belongs to that <span>control group owner
-  object</span>'s <span>control group</span>. Otherwise, the <span>focusable area</span> belongs to its
-  <span>DOM anchor</span>'s nearest ancestor <span>control group owner object</span>.</p>
+  <p>Each <span>focusable area</span> belongs to a single <span>control group</span> as follows. If
+  the <span>DOM anchor</span> of a <span>focusable area</span> is a <span>control group
+  owner object</span>, then that <span>focusable area</span> belongs to that <span>control group
+  owner object</span>'s <span>control group</span>. Otherwise, the <span>focusable area</span>
+  belongs to its <span>DOM anchor</span>'s nearest ancestor <span>control group owner
+  object</span>'s <span>control group</span>.</p>
 
   <div class="example">
 
@@ -71333,6 +71336,9 @@ END:VCARD</pre>
 
   </div>
 
+  <p class="note">It is possible for a <span>control group</span> to be empty, i.e. for it to have
+  no <span data-x="focusable area">focusable areas</span>.</p>
+
   <p>An element is <dfn data-x="expressly inert control">expressly inert</dfn> if it is
   <span>inert</span> but it is not a <span>control group owner object</span> and its nearest
   ancestor <span>control group owner object</span> is not <span>inert</span>.</p>
@@ -71443,7 +71449,8 @@ END:VCARD</pre>
 
     <p>Otherwise, if <var>current object</var> is a <span>focusable area</span>, let <var>current
     object</var> be that <span>focusable area</span>'s <span>control group</span>'s <span
-    data-x="control group owner">owner</span>, and return to the step labeled <i>loop</i>.</p>
+    data-x="control group owner object">owner object</span>, and return to the step labeled
+    <i>loop</i>.</p>
 
     <p>Otherwise, if <var>current object</var> is a <code>Document</code> in a <span>nested browsing
     context</span>, let <var>current object</var> be its <span>browsing context container</span>,
@@ -71815,8 +71822,8 @@ END:VCARD</pre>
 
     <p>Otherwise, if <var>old focus target</var> is a <span>focusable area</span>, then let <var>new
     focus target</var> be the first <span>focusable area</span> of its <span>control group</span>
-    (if the <span>control group owner</span> is a <code>Document</code>, this will always be a
-    viewport).</p>
+    (if the <span>control group owner object</span> is a <code>Document</code>, this will always be
+    a viewport).</p>
 
     <p>Otherwise, let <var>new focus target</var> be null.</p>
 
@@ -71999,14 +72006,15 @@ END:VCARD</pre>
 
      <li>
 
-      <p>If <var>entry</var> is a <span>focusable area</span>: Designate <var>entry</var> as the <span>focused area of the control group</span>. If its <span>control
-      group</span>'s <span data-x="control group owner">owner</span> is also a <span>dialog group
+      <p>If <var>entry</var> is a <span>focusable area</span>: Designate <var>entry</var> as the
+      <span>focused area of the control group</span>. If its <span>control group</span>'s <span
+      data-x="control group owner object">owner object</span> is also a <span>dialog group
       manager</span>, then let there be no designated <span data-x="focused dialog of the dialog
       group">focused dialog</span> in that <span>dialog group</span>.</p>
 
       <p class="note">It is possible for <var>entry</var> to be both a <code>dialog</code>
       element and a <span>focusable area</span>, in which case it is its own <span>control group
-      owner</span>.</p>
+      owner object</span>.</p>
 
      </li>