diff --git a/complete.html b/complete.html
index 68ca5ffcb84..2c279fcdf4a 100644
--- a/complete.html
+++ b/complete.html
@@ -19797,11 +19797,11 @@ <h4 id=the-iframe-element>4.8.6 The <dfn><code>iframe</code></dfn> element</h4>
   <hr> 
 
   <p>When an <code id=the-iframe-element:the-iframe-element-7><a href=#the-iframe-element>iframe</a></code> element is <a href=#insert-an-element-into-a-document id=the-iframe-element:insert-an-element-into-a-document>inserted
-  into a document</a>, the user agent must create a <a href=#nested-browsing-context id=the-iframe-element:nested-browsing-context-5>nested browsing context</a>, and
+  into a document</a> that has a <a href=#browsing-context id=the-iframe-element:browsing-context>browsing context</a>, the user agent must create a <a href=#nested-browsing-context id=the-iframe-element:nested-browsing-context-5>nested browsing context</a>, and
   then <a href=#process-the-iframe-attributes id=the-iframe-element:process-the-iframe-attributes>process the <code>iframe</code> attributes</a> for the "first time".</p>
 
   <p>When an <code id=the-iframe-element:the-iframe-element-8><a href=#the-iframe-element>iframe</a></code> element is <a href=#remove-an-element-from-a-document id=the-iframe-element:remove-an-element-from-a-document>removed
-  from a document</a>, the user agent must <a href=#a-browsing-context-is-discarded id=the-iframe-element:a-browsing-context-is-discarded>discard</a> the <a href=#nested-browsing-context id=the-iframe-element:nested-browsing-context-6>nested browsing context</a>.</p>
+  from a document</a>, the user agent must <a href=#a-browsing-context-is-discarded id=the-iframe-element:a-browsing-context-is-discarded>discard</a> the <a href=#nested-browsing-context id=the-iframe-element:nested-browsing-context-6>nested browsing context</a>, if any.</p>
 
   <p class=note>This happens without any <code id=the-iframe-element:event-unload><a href=#event-unload>unload</a></code> events firing
   (the <a href=#nested-browsing-context id=the-iframe-element:nested-browsing-context-7>nested browsing context</a> and its <code id=the-iframe-element:document-2><a href=#document>Document</a></code> are <em><a href=#a-browsing-context-is-discarded id=the-iframe-element:a-browsing-context-is-discarded-2>discarded</a></em>, not <em><span> data-x="unload a
@@ -19868,7 +19868,7 @@ <h4 id=the-iframe-element>4.8.6 The <dfn><code>iframe</code></dfn> element</h4>
   <p>Any <a href=#navigate id=the-iframe-element:navigate-3>navigation</a> required of the user agent in the <a href=#process-the-iframe-attributes id=the-iframe-element:process-the-iframe-attributes-4>process
   the <code>iframe</code> attributes</a> algorithm must be completed as an <a href=#explicit-self-navigation-override id=the-iframe-element:explicit-self-navigation-override>explicit
   self-navigation override</a> and with the <code id=the-iframe-element:the-iframe-element-13><a href=#the-iframe-element>iframe</a></code> element's document's
-  <a href=#browsing-context id=the-iframe-element:browsing-context>browsing context</a> as the <a href=#source-browsing-context id=the-iframe-element:source-browsing-context>source browsing context</a>.</p>
+  <a href=#browsing-context id=the-iframe-element:browsing-context-2>browsing context</a> as the <a href=#source-browsing-context id=the-iframe-element:source-browsing-context>source browsing context</a>.</p>
 
   <p>Furthermore, if the <a href=#active-document id=the-iframe-element:active-document-2>active document</a> of the element's <a href=#child-browsing-context id=the-iframe-element:child-browsing-context-3>child browsing
   context</a> before such a <a href=#navigate id=the-iframe-element:navigate-4>navigation</a> was not <a href=#completely-loaded id=the-iframe-element:completely-loaded>completely
@@ -19904,14 +19904,14 @@ <h4 id=the-iframe-element>4.8.6 The <dfn><code>iframe</code></dfn> element</h4>
   access control policies that are stricter than those described above to mitigate this attack, but
   unfortunately such policies are typically not compatible with existing Web content.</p>
 
-  <p>When the <code id=the-iframe-element:the-iframe-element-18><a href=#the-iframe-element>iframe</a></code>'s <a href=#browsing-context id=the-iframe-element:browsing-context-2>browsing context</a>'s <a href=#active-document id=the-iframe-element:active-document-4>active document</a> is
+  <p>When the <code id=the-iframe-element:the-iframe-element-18><a href=#the-iframe-element>iframe</a></code>'s <a href=#browsing-context id=the-iframe-element:browsing-context-3>browsing context</a>'s <a href=#active-document id=the-iframe-element:active-document-4>active document</a> is
   not <a href=#ready-for-post-load-tasks id=the-iframe-element:ready-for-post-load-tasks>ready for post-load tasks</a>, and when anything in the <code id=the-iframe-element:the-iframe-element-19><a href=#the-iframe-element>iframe</a></code> is <a href=#delay-the-load-event id=the-iframe-element:delay-the-load-event>delaying the load event</a> of the <code id=the-iframe-element:the-iframe-element-20><a href=#the-iframe-element>iframe</a></code>'s
-  <a href=#browsing-context id=the-iframe-element:browsing-context-3>browsing context</a>'s <a href=#active-document id=the-iframe-element:active-document-5>active document</a>, and when the <code id=the-iframe-element:the-iframe-element-21><a href=#the-iframe-element>iframe</a></code>'s
-  <a href=#browsing-context id=the-iframe-element:browsing-context-4>browsing context</a> is in the <a href=#delaying-load-events-mode id=the-iframe-element:delaying-load-events-mode>delaying <code>load</code> events
+  <a href=#browsing-context id=the-iframe-element:browsing-context-4>browsing context</a>'s <a href=#active-document id=the-iframe-element:active-document-5>active document</a>, and when the <code id=the-iframe-element:the-iframe-element-21><a href=#the-iframe-element>iframe</a></code>'s
+  <a href=#browsing-context id=the-iframe-element:browsing-context-5>browsing context</a> is in the <a href=#delaying-load-events-mode id=the-iframe-element:delaying-load-events-mode>delaying <code>load</code> events
   mode</a>, the <code id=the-iframe-element:the-iframe-element-22><a href=#the-iframe-element>iframe</a></code> must <a href=#delay-the-load-event id=the-iframe-element:delay-the-load-event-2>delay the load event</a> of its document.</p>
 
   <p class=note>If, during the handling of the <code id=the-iframe-element:event-load-3><a href=#event-load>load</a></code> event, the
-  <a href=#browsing-context id=the-iframe-element:browsing-context-5>browsing context</a> in the <code id=the-iframe-element:the-iframe-element-23><a href=#the-iframe-element>iframe</a></code> is again <a href=#navigate id=the-iframe-element:navigate-8>navigated</a>, that will further <a href=#delay-the-load-event id=the-iframe-element:delay-the-load-event-3>delay the load event</a>.</p>
+  <a href=#browsing-context id=the-iframe-element:browsing-context-6>browsing context</a> in the <code id=the-iframe-element:the-iframe-element-23><a href=#the-iframe-element>iframe</a></code> is again <a href=#navigate id=the-iframe-element:navigate-8>navigated</a>, that will further <a href=#delay-the-load-event id=the-iframe-element:delay-the-load-event-3>delay the load event</a>.</p>
 
   
 
@@ -19937,7 +19937,7 @@ <h4 id=the-iframe-element>4.8.6 The <dfn><code>iframe</code></dfn> element</h4>
   
 
   <p>Whenever the <code id=the-iframe-element:attr-iframe-name-2><a href=#attr-iframe-name>name</a></code> attribute is set, the nested
-  <a href=#browsing-context id=the-iframe-element:browsing-context-6>browsing context</a>'s <a href=#browsing-context-name id=the-iframe-element:browsing-context-name-3>name</a> must be changed to
+  <a href=#browsing-context id=the-iframe-element:browsing-context-7>browsing context</a>'s <a href=#browsing-context-name id=the-iframe-element:browsing-context-name-3>name</a> must be changed to
   the new value. If the attribute is removed, the <a href=#browsing-context-name id=the-iframe-element:browsing-context-name-4>browsing context name</a> must be set to
   the empty string.</p>
 
@@ -19953,7 +19953,7 @@ <h4 id=the-iframe-element>4.8.6 The <dfn><code>iframe</code></dfn> element</h4>
 
   <p>When the attribute is set, the content is treated as being from a unique <a href=#origin-2 id=the-iframe-element:origin-2-2>origin</a>,
   forms, scripts, and various potentially annoying APIs are disabled, links are prevented from
-  targeting other <a href=#browsing-context id=the-iframe-element:browsing-context-7>browsing contexts</a>, and plugins are secured.
+  targeting other <a href=#browsing-context id=the-iframe-element:browsing-context-8>browsing contexts</a>, and plugins are secured.
   The <code id=the-iframe-element:attr-iframe-sandbox-allow-same-origin-2><a href=#attr-iframe-sandbox-allow-same-origin>allow-same-origin</a></code> keyword causes
   the content to be treated as being from its real origin instead of forcing it into a unique
   origin; the <code id=the-iframe-element:attr-iframe-sandbox-allow-top-navigation-2><a href=#attr-iframe-sandbox-allow-top-navigation>allow-top-navigation</a></code>
@@ -20067,7 +20067,7 @@ <h4 id=the-iframe-element>4.8.6 The <dfn><code>iframe</code></dfn> element</h4>
 
   <p>The <dfn id=attr-iframe-seamless><code>seamless</code></dfn> attribute is a <a href=#boolean-attribute id=the-iframe-element:boolean-attribute>boolean
   attribute</a>. When specified, it indicates that the <code id=the-iframe-element:the-iframe-element-42><a href=#the-iframe-element>iframe</a></code> element's
-  <a href=#browsing-context id=the-iframe-element:browsing-context-8>browsing context</a> is to be rendered in a manner that makes it appear to be part of the
+  <a href=#browsing-context id=the-iframe-element:browsing-context-9>browsing context</a> is to be rendered in a manner that makes it appear to be part of the
   containing document (seamlessly included in the parent document).</p>
 
   <div class=example>
@@ -20109,13 +20109,13 @@ <h4 id=the-iframe-element>4.8.6 The <dfn><code>iframe</code></dfn> element</h4>
 
    <li>Either:
 
-    <ul><li>The <a href=#browsing-context id=the-iframe-element:browsing-context-9>browsing context</a>'s <a href=#active-document id=the-iframe-element:active-document-6>active document</a> has the <a href=#same-origin id=the-iframe-element:same-origin-2>same
+    <ul><li>The <a href=#browsing-context id=the-iframe-element:browsing-context-10>browsing context</a>'s <a href=#active-document id=the-iframe-element:active-document-6>active document</a> has the <a href=#same-origin id=the-iframe-element:same-origin-2>same
      origin</a> as the <code id=the-iframe-element:the-iframe-element-48><a href=#the-iframe-element>iframe</a></code> element's <code id=the-iframe-element:document-13><a href=#document>Document</a></code>, or
 
-     <li>The <a href=#browsing-context id=the-iframe-element:browsing-context-10>browsing context</a>'s <a href=#active-document id=the-iframe-element:active-document-7>active document</a>'s <em><a href=http://dom.spec.whatwg.org/#concept-document-url id="the-iframe-element:the-document's-address-2" data-x-internal="the-document's-address">address</a></em> has the <a href=#same-origin id=the-iframe-element:same-origin-3>same origin</a> as the
+     <li>The <a href=#browsing-context id=the-iframe-element:browsing-context-11>browsing context</a>'s <a href=#active-document id=the-iframe-element:active-document-7>active document</a>'s <em><a href=http://dom.spec.whatwg.org/#concept-document-url id="the-iframe-element:the-document's-address-2" data-x-internal="the-document's-address">address</a></em> has the <a href=#same-origin id=the-iframe-element:same-origin-3>same origin</a> as the
      <code id=the-iframe-element:the-iframe-element-49><a href=#the-iframe-element>iframe</a></code> element's <code id=the-iframe-element:document-14><a href=#document>Document</a></code>, or
 
-     <li>The <a href=#browsing-context id=the-iframe-element:browsing-context-11>browsing context</a>'s <a href=#active-document id=the-iframe-element:active-document-8>active document</a> is <a href=#an-iframe-srcdoc-document id=the-iframe-element:an-iframe-srcdoc-document-4>an
+     <li>The <a href=#browsing-context id=the-iframe-element:browsing-context-12>browsing context</a>'s <a href=#active-document id=the-iframe-element:active-document-8>active document</a> is <a href=#an-iframe-srcdoc-document id=the-iframe-element:an-iframe-srcdoc-document-4>an
      <code>iframe</code> <code>srcdoc</code> document</a>.
 
     </ul>
@@ -20126,9 +20126,9 @@ <h4 id=the-iframe-element>4.8.6 The <dfn><code>iframe</code></dfn> element</h4>
   requirements apply:</p>
 
   <ul><li><p>The user agent must set the <dfn id=seamless-browsing-context-flag>seamless browsing context flag</dfn> to true for that
-   <a href=#browsing-context id=the-iframe-element:browsing-context-12>browsing context</a>. This will <a href=#seamlessLinks>cause links to open in the
+   <a href=#browsing-context id=the-iframe-element:browsing-context-13>browsing context</a>. This will <a href=#seamlessLinks>cause links to open in the
    parent browsing context</a> unless an <a href=#explicit-self-navigation-override id=the-iframe-element:explicit-self-navigation-override-2>explicit self-navigation override</a> is used
-   (<code>target="_self"</code>).<li><p>Media queries in the context of the <code id=the-iframe-element:the-iframe-element-51><a href=#the-iframe-element>iframe</a></code>'s <a href=#browsing-context id=the-iframe-element:browsing-context-13>browsing context</a>
+   (<code>target="_self"</code>).<li><p>Media queries in the context of the <code id=the-iframe-element:the-iframe-element-51><a href=#the-iframe-element>iframe</a></code>'s <a href=#browsing-context id=the-iframe-element:browsing-context-14>browsing context</a>
    (e.g. on <code id=the-iframe-element:attr-style-media><a href=#attr-style-media>media</a></code> attributes of <code id=the-iframe-element:the-style-element><a href=#the-style-element>style</a></code> elements in
    <code id=the-iframe-element:document-15><a href=#document>Document</a></code>s in that <code id=the-iframe-element:the-iframe-element-52><a href=#the-iframe-element>iframe</a></code>) must be evaluated with respect to the nearest
    <a href=#ancestor-browsing-context id=the-iframe-element:ancestor-browsing-context-2>ancestor browsing context</a> that is not itself being <a href=#browsing-context-nested-through id=the-iframe-element:browsing-context-nested-through>nested through</a> an <code id=the-iframe-element:the-iframe-element-53><a href=#the-iframe-element>iframe</a></code> that is <a href=#in-seamless-mode id=the-iframe-element:in-seamless-mode-2>in seamless
@@ -20176,8 +20176,8 @@ <h4 id=the-iframe-element>4.8.6 The <dfn><code>iframe</code></dfn> element</h4>
 
   <p>If the attribute is not specified, or if the <a href=#origin-2 id=the-iframe-element:origin-2-3>origin</a> conditions listed above are
   not met, then the user agent should render the <a href=#nested-browsing-context id=the-iframe-element:nested-browsing-context-25>nested browsing context</a> in a manner
-  that is clearly distinguishable as a separate <a href=#browsing-context id=the-iframe-element:browsing-context-14>browsing context</a>, and the
-  <a href=#seamless-browsing-context-flag id=the-iframe-element:seamless-browsing-context-flag>seamless browsing context flag</a> must be set to false for that <a href=#browsing-context id=the-iframe-element:browsing-context-15>browsing
+  that is clearly distinguishable as a separate <a href=#browsing-context id=the-iframe-element:browsing-context-15>browsing context</a>, and the
+  <a href=#seamless-browsing-context-flag id=the-iframe-element:seamless-browsing-context-flag>seamless browsing context flag</a> must be set to false for that <a href=#browsing-context id=the-iframe-element:browsing-context-16>browsing
   context</a>.</p>
 
   <p class=warning>It is important that user agents recheck the above conditions whenever the
@@ -20199,7 +20199,7 @@ <h4 id=the-iframe-element>4.8.6 The <dfn><code>iframe</code></dfn> element</h4>
 
   <p>The <dfn id=attr-iframe-allowfullscreen><code>allowfullscreen</code></dfn> attribute is a
   <a href=#boolean-attribute id=the-iframe-element:boolean-attribute-2>boolean attribute</a>. When specified, it indicates that <code id=the-iframe-element:document-16><a href=#document>Document</a></code> objects in
-  the <code id=the-iframe-element:the-iframe-element-70><a href=#the-iframe-element>iframe</a></code> element's <a href=#browsing-context id=the-iframe-element:browsing-context-16>browsing context</a> are to be allowed to use <code id=the-iframe-element:dom-element-requestfullscreen-2><a href=#dom-element-requestfullscreen>requestFullscreen()</a></code> (if it's not blocked for other
+  the <code id=the-iframe-element:the-iframe-element-70><a href=#the-iframe-element>iframe</a></code> element's <a href=#browsing-context id=the-iframe-element:browsing-context-17>browsing context</a> are to be allowed to use <code id=the-iframe-element:dom-element-requestfullscreen-2><a href=#dom-element-requestfullscreen>requestFullscreen()</a></code> (if it's not blocked for other
   reasons, e.g. there is another ancestor <code id=the-iframe-element:the-iframe-element-71><a href=#the-iframe-element>iframe</a></code> without this attribute set).</p>
 
   <div class=example>
@@ -20227,7 +20227,7 @@ <h4 id=the-iframe-element>4.8.6 The <dfn><code>iframe</code></dfn> element</h4>
   embedded content has specific dimensions (e.g. ad units have well-defined dimensions).</p>
 
   <p>An <code id=the-iframe-element:the-iframe-element-74><a href=#the-iframe-element>iframe</a></code> element never has <a href=#fallback-content id=the-iframe-element:fallback-content>fallback content</a>, as it will always
-  create a nested <a href=#browsing-context id=the-iframe-element:browsing-context-17>browsing context</a>, regardless of whether the specified initial
+  create a nested <a href=#browsing-context id=the-iframe-element:browsing-context-18>browsing context</a>, regardless of whether the specified initial
   contents are successfully used.</p>
 
 
diff --git a/index b/index
index 68ca5ffcb84..2c279fcdf4a 100644
--- a/index
+++ b/index
@@ -19797,11 +19797,11 @@ href="?audio">audio&lt;/a> test instead.)&lt;/p></pre>
   <hr> 
 
   <p>When an <code id=the-iframe-element:the-iframe-element-7><a href=#the-iframe-element>iframe</a></code> element is <a href=#insert-an-element-into-a-document id=the-iframe-element:insert-an-element-into-a-document>inserted
-  into a document</a>, the user agent must create a <a href=#nested-browsing-context id=the-iframe-element:nested-browsing-context-5>nested browsing context</a>, and
+  into a document</a> that has a <a href=#browsing-context id=the-iframe-element:browsing-context>browsing context</a>, the user agent must create a <a href=#nested-browsing-context id=the-iframe-element:nested-browsing-context-5>nested browsing context</a>, and
   then <a href=#process-the-iframe-attributes id=the-iframe-element:process-the-iframe-attributes>process the <code>iframe</code> attributes</a> for the "first time".</p>
 
   <p>When an <code id=the-iframe-element:the-iframe-element-8><a href=#the-iframe-element>iframe</a></code> element is <a href=#remove-an-element-from-a-document id=the-iframe-element:remove-an-element-from-a-document>removed
-  from a document</a>, the user agent must <a href=#a-browsing-context-is-discarded id=the-iframe-element:a-browsing-context-is-discarded>discard</a> the <a href=#nested-browsing-context id=the-iframe-element:nested-browsing-context-6>nested browsing context</a>.</p>
+  from a document</a>, the user agent must <a href=#a-browsing-context-is-discarded id=the-iframe-element:a-browsing-context-is-discarded>discard</a> the <a href=#nested-browsing-context id=the-iframe-element:nested-browsing-context-6>nested browsing context</a>, if any.</p>
 
   <p class=note>This happens without any <code id=the-iframe-element:event-unload><a href=#event-unload>unload</a></code> events firing
   (the <a href=#nested-browsing-context id=the-iframe-element:nested-browsing-context-7>nested browsing context</a> and its <code id=the-iframe-element:document-2><a href=#document>Document</a></code> are <em><a href=#a-browsing-context-is-discarded id=the-iframe-element:a-browsing-context-is-discarded-2>discarded</a></em>, not <em><span> data-x="unload a
@@ -19868,7 +19868,7 @@ href="?audio">audio&lt;/a> test instead.)&lt;/p></pre>
   <p>Any <a href=#navigate id=the-iframe-element:navigate-3>navigation</a> required of the user agent in the <a href=#process-the-iframe-attributes id=the-iframe-element:process-the-iframe-attributes-4>process
   the <code>iframe</code> attributes</a> algorithm must be completed as an <a href=#explicit-self-navigation-override id=the-iframe-element:explicit-self-navigation-override>explicit
   self-navigation override</a> and with the <code id=the-iframe-element:the-iframe-element-13><a href=#the-iframe-element>iframe</a></code> element's document's
-  <a href=#browsing-context id=the-iframe-element:browsing-context>browsing context</a> as the <a href=#source-browsing-context id=the-iframe-element:source-browsing-context>source browsing context</a>.</p>
+  <a href=#browsing-context id=the-iframe-element:browsing-context-2>browsing context</a> as the <a href=#source-browsing-context id=the-iframe-element:source-browsing-context>source browsing context</a>.</p>
 
   <p>Furthermore, if the <a href=#active-document id=the-iframe-element:active-document-2>active document</a> of the element's <a href=#child-browsing-context id=the-iframe-element:child-browsing-context-3>child browsing
   context</a> before such a <a href=#navigate id=the-iframe-element:navigate-4>navigation</a> was not <a href=#completely-loaded id=the-iframe-element:completely-loaded>completely
@@ -19904,14 +19904,14 @@ href="?audio">audio&lt;/a> test instead.)&lt;/p></pre>
   access control policies that are stricter than those described above to mitigate this attack, but
   unfortunately such policies are typically not compatible with existing Web content.</p>
 
-  <p>When the <code id=the-iframe-element:the-iframe-element-18><a href=#the-iframe-element>iframe</a></code>'s <a href=#browsing-context id=the-iframe-element:browsing-context-2>browsing context</a>'s <a href=#active-document id=the-iframe-element:active-document-4>active document</a> is
+  <p>When the <code id=the-iframe-element:the-iframe-element-18><a href=#the-iframe-element>iframe</a></code>'s <a href=#browsing-context id=the-iframe-element:browsing-context-3>browsing context</a>'s <a href=#active-document id=the-iframe-element:active-document-4>active document</a> is
   not <a href=#ready-for-post-load-tasks id=the-iframe-element:ready-for-post-load-tasks>ready for post-load tasks</a>, and when anything in the <code id=the-iframe-element:the-iframe-element-19><a href=#the-iframe-element>iframe</a></code> is <a href=#delay-the-load-event id=the-iframe-element:delay-the-load-event>delaying the load event</a> of the <code id=the-iframe-element:the-iframe-element-20><a href=#the-iframe-element>iframe</a></code>'s
-  <a href=#browsing-context id=the-iframe-element:browsing-context-3>browsing context</a>'s <a href=#active-document id=the-iframe-element:active-document-5>active document</a>, and when the <code id=the-iframe-element:the-iframe-element-21><a href=#the-iframe-element>iframe</a></code>'s
-  <a href=#browsing-context id=the-iframe-element:browsing-context-4>browsing context</a> is in the <a href=#delaying-load-events-mode id=the-iframe-element:delaying-load-events-mode>delaying <code>load</code> events
+  <a href=#browsing-context id=the-iframe-element:browsing-context-4>browsing context</a>'s <a href=#active-document id=the-iframe-element:active-document-5>active document</a>, and when the <code id=the-iframe-element:the-iframe-element-21><a href=#the-iframe-element>iframe</a></code>'s
+  <a href=#browsing-context id=the-iframe-element:browsing-context-5>browsing context</a> is in the <a href=#delaying-load-events-mode id=the-iframe-element:delaying-load-events-mode>delaying <code>load</code> events
   mode</a>, the <code id=the-iframe-element:the-iframe-element-22><a href=#the-iframe-element>iframe</a></code> must <a href=#delay-the-load-event id=the-iframe-element:delay-the-load-event-2>delay the load event</a> of its document.</p>
 
   <p class=note>If, during the handling of the <code id=the-iframe-element:event-load-3><a href=#event-load>load</a></code> event, the
-  <a href=#browsing-context id=the-iframe-element:browsing-context-5>browsing context</a> in the <code id=the-iframe-element:the-iframe-element-23><a href=#the-iframe-element>iframe</a></code> is again <a href=#navigate id=the-iframe-element:navigate-8>navigated</a>, that will further <a href=#delay-the-load-event id=the-iframe-element:delay-the-load-event-3>delay the load event</a>.</p>
+  <a href=#browsing-context id=the-iframe-element:browsing-context-6>browsing context</a> in the <code id=the-iframe-element:the-iframe-element-23><a href=#the-iframe-element>iframe</a></code> is again <a href=#navigate id=the-iframe-element:navigate-8>navigated</a>, that will further <a href=#delay-the-load-event id=the-iframe-element:delay-the-load-event-3>delay the load event</a>.</p>
 
   
 
@@ -19937,7 +19937,7 @@ href="?audio">audio&lt;/a> test instead.)&lt;/p></pre>
   
 
   <p>Whenever the <code id=the-iframe-element:attr-iframe-name-2><a href=#attr-iframe-name>name</a></code> attribute is set, the nested
-  <a href=#browsing-context id=the-iframe-element:browsing-context-6>browsing context</a>'s <a href=#browsing-context-name id=the-iframe-element:browsing-context-name-3>name</a> must be changed to
+  <a href=#browsing-context id=the-iframe-element:browsing-context-7>browsing context</a>'s <a href=#browsing-context-name id=the-iframe-element:browsing-context-name-3>name</a> must be changed to
   the new value. If the attribute is removed, the <a href=#browsing-context-name id=the-iframe-element:browsing-context-name-4>browsing context name</a> must be set to
   the empty string.</p>
 
@@ -19953,7 +19953,7 @@ href="?audio">audio&lt;/a> test instead.)&lt;/p></pre>
 
   <p>When the attribute is set, the content is treated as being from a unique <a href=#origin-2 id=the-iframe-element:origin-2-2>origin</a>,
   forms, scripts, and various potentially annoying APIs are disabled, links are prevented from
-  targeting other <a href=#browsing-context id=the-iframe-element:browsing-context-7>browsing contexts</a>, and plugins are secured.
+  targeting other <a href=#browsing-context id=the-iframe-element:browsing-context-8>browsing contexts</a>, and plugins are secured.
   The <code id=the-iframe-element:attr-iframe-sandbox-allow-same-origin-2><a href=#attr-iframe-sandbox-allow-same-origin>allow-same-origin</a></code> keyword causes
   the content to be treated as being from its real origin instead of forcing it into a unique
   origin; the <code id=the-iframe-element:attr-iframe-sandbox-allow-top-navigation-2><a href=#attr-iframe-sandbox-allow-top-navigation>allow-top-navigation</a></code>
@@ -20067,7 +20067,7 @@ href="?audio">audio&lt;/a> test instead.)&lt;/p></pre>
 
   <p>The <dfn id=attr-iframe-seamless><code>seamless</code></dfn> attribute is a <a href=#boolean-attribute id=the-iframe-element:boolean-attribute>boolean
   attribute</a>. When specified, it indicates that the <code id=the-iframe-element:the-iframe-element-42><a href=#the-iframe-element>iframe</a></code> element's
-  <a href=#browsing-context id=the-iframe-element:browsing-context-8>browsing context</a> is to be rendered in a manner that makes it appear to be part of the
+  <a href=#browsing-context id=the-iframe-element:browsing-context-9>browsing context</a> is to be rendered in a manner that makes it appear to be part of the
   containing document (seamlessly included in the parent document).</p>
 
   <div class=example>
@@ -20109,13 +20109,13 @@ href="?audio">audio&lt;/a> test instead.)&lt;/p></pre>
 
    <li>Either:
 
-    <ul><li>The <a href=#browsing-context id=the-iframe-element:browsing-context-9>browsing context</a>'s <a href=#active-document id=the-iframe-element:active-document-6>active document</a> has the <a href=#same-origin id=the-iframe-element:same-origin-2>same
+    <ul><li>The <a href=#browsing-context id=the-iframe-element:browsing-context-10>browsing context</a>'s <a href=#active-document id=the-iframe-element:active-document-6>active document</a> has the <a href=#same-origin id=the-iframe-element:same-origin-2>same
      origin</a> as the <code id=the-iframe-element:the-iframe-element-48><a href=#the-iframe-element>iframe</a></code> element's <code id=the-iframe-element:document-13><a href=#document>Document</a></code>, or
 
-     <li>The <a href=#browsing-context id=the-iframe-element:browsing-context-10>browsing context</a>'s <a href=#active-document id=the-iframe-element:active-document-7>active document</a>'s <em><a href=http://dom.spec.whatwg.org/#concept-document-url id="the-iframe-element:the-document's-address-2" data-x-internal="the-document's-address">address</a></em> has the <a href=#same-origin id=the-iframe-element:same-origin-3>same origin</a> as the
+     <li>The <a href=#browsing-context id=the-iframe-element:browsing-context-11>browsing context</a>'s <a href=#active-document id=the-iframe-element:active-document-7>active document</a>'s <em><a href=http://dom.spec.whatwg.org/#concept-document-url id="the-iframe-element:the-document's-address-2" data-x-internal="the-document's-address">address</a></em> has the <a href=#same-origin id=the-iframe-element:same-origin-3>same origin</a> as the
      <code id=the-iframe-element:the-iframe-element-49><a href=#the-iframe-element>iframe</a></code> element's <code id=the-iframe-element:document-14><a href=#document>Document</a></code>, or
 
-     <li>The <a href=#browsing-context id=the-iframe-element:browsing-context-11>browsing context</a>'s <a href=#active-document id=the-iframe-element:active-document-8>active document</a> is <a href=#an-iframe-srcdoc-document id=the-iframe-element:an-iframe-srcdoc-document-4>an
+     <li>The <a href=#browsing-context id=the-iframe-element:browsing-context-12>browsing context</a>'s <a href=#active-document id=the-iframe-element:active-document-8>active document</a> is <a href=#an-iframe-srcdoc-document id=the-iframe-element:an-iframe-srcdoc-document-4>an
      <code>iframe</code> <code>srcdoc</code> document</a>.
 
     </ul>
@@ -20126,9 +20126,9 @@ href="?audio">audio&lt;/a> test instead.)&lt;/p></pre>
   requirements apply:</p>
 
   <ul><li><p>The user agent must set the <dfn id=seamless-browsing-context-flag>seamless browsing context flag</dfn> to true for that
-   <a href=#browsing-context id=the-iframe-element:browsing-context-12>browsing context</a>. This will <a href=#seamlessLinks>cause links to open in the
+   <a href=#browsing-context id=the-iframe-element:browsing-context-13>browsing context</a>. This will <a href=#seamlessLinks>cause links to open in the
    parent browsing context</a> unless an <a href=#explicit-self-navigation-override id=the-iframe-element:explicit-self-navigation-override-2>explicit self-navigation override</a> is used
-   (<code>target="_self"</code>).<li><p>Media queries in the context of the <code id=the-iframe-element:the-iframe-element-51><a href=#the-iframe-element>iframe</a></code>'s <a href=#browsing-context id=the-iframe-element:browsing-context-13>browsing context</a>
+   (<code>target="_self"</code>).<li><p>Media queries in the context of the <code id=the-iframe-element:the-iframe-element-51><a href=#the-iframe-element>iframe</a></code>'s <a href=#browsing-context id=the-iframe-element:browsing-context-14>browsing context</a>
    (e.g. on <code id=the-iframe-element:attr-style-media><a href=#attr-style-media>media</a></code> attributes of <code id=the-iframe-element:the-style-element><a href=#the-style-element>style</a></code> elements in
    <code id=the-iframe-element:document-15><a href=#document>Document</a></code>s in that <code id=the-iframe-element:the-iframe-element-52><a href=#the-iframe-element>iframe</a></code>) must be evaluated with respect to the nearest
    <a href=#ancestor-browsing-context id=the-iframe-element:ancestor-browsing-context-2>ancestor browsing context</a> that is not itself being <a href=#browsing-context-nested-through id=the-iframe-element:browsing-context-nested-through>nested through</a> an <code id=the-iframe-element:the-iframe-element-53><a href=#the-iframe-element>iframe</a></code> that is <a href=#in-seamless-mode id=the-iframe-element:in-seamless-mode-2>in seamless
@@ -20176,8 +20176,8 @@ href="?audio">audio&lt;/a> test instead.)&lt;/p></pre>
 
   <p>If the attribute is not specified, or if the <a href=#origin-2 id=the-iframe-element:origin-2-3>origin</a> conditions listed above are
   not met, then the user agent should render the <a href=#nested-browsing-context id=the-iframe-element:nested-browsing-context-25>nested browsing context</a> in a manner
-  that is clearly distinguishable as a separate <a href=#browsing-context id=the-iframe-element:browsing-context-14>browsing context</a>, and the
-  <a href=#seamless-browsing-context-flag id=the-iframe-element:seamless-browsing-context-flag>seamless browsing context flag</a> must be set to false for that <a href=#browsing-context id=the-iframe-element:browsing-context-15>browsing
+  that is clearly distinguishable as a separate <a href=#browsing-context id=the-iframe-element:browsing-context-15>browsing context</a>, and the
+  <a href=#seamless-browsing-context-flag id=the-iframe-element:seamless-browsing-context-flag>seamless browsing context flag</a> must be set to false for that <a href=#browsing-context id=the-iframe-element:browsing-context-16>browsing
   context</a>.</p>
 
   <p class=warning>It is important that user agents recheck the above conditions whenever the
@@ -20199,7 +20199,7 @@ href="?audio">audio&lt;/a> test instead.)&lt;/p></pre>
 
   <p>The <dfn id=attr-iframe-allowfullscreen><code>allowfullscreen</code></dfn> attribute is a
   <a href=#boolean-attribute id=the-iframe-element:boolean-attribute-2>boolean attribute</a>. When specified, it indicates that <code id=the-iframe-element:document-16><a href=#document>Document</a></code> objects in
-  the <code id=the-iframe-element:the-iframe-element-70><a href=#the-iframe-element>iframe</a></code> element's <a href=#browsing-context id=the-iframe-element:browsing-context-16>browsing context</a> are to be allowed to use <code id=the-iframe-element:dom-element-requestfullscreen-2><a href=#dom-element-requestfullscreen>requestFullscreen()</a></code> (if it's not blocked for other
+  the <code id=the-iframe-element:the-iframe-element-70><a href=#the-iframe-element>iframe</a></code> element's <a href=#browsing-context id=the-iframe-element:browsing-context-17>browsing context</a> are to be allowed to use <code id=the-iframe-element:dom-element-requestfullscreen-2><a href=#dom-element-requestfullscreen>requestFullscreen()</a></code> (if it's not blocked for other
   reasons, e.g. there is another ancestor <code id=the-iframe-element:the-iframe-element-71><a href=#the-iframe-element>iframe</a></code> without this attribute set).</p>
 
   <div class=example>
@@ -20227,7 +20227,7 @@ href="?audio">audio&lt;/a> test instead.)&lt;/p></pre>
   embedded content has specific dimensions (e.g. ad units have well-defined dimensions).</p>
 
   <p>An <code id=the-iframe-element:the-iframe-element-74><a href=#the-iframe-element>iframe</a></code> element never has <a href=#fallback-content id=the-iframe-element:fallback-content>fallback content</a>, as it will always
-  create a nested <a href=#browsing-context id=the-iframe-element:browsing-context-17>browsing context</a>, regardless of whether the specified initial
+  create a nested <a href=#browsing-context id=the-iframe-element:browsing-context-18>browsing context</a>, regardless of whether the specified initial
   contents are successfully used.</p>
 
 
diff --git a/source b/source
index 94db988474d..4ac01ee4015 100644
--- a/source
+++ b/source
@@ -24760,12 +24760,12 @@ href="?audio">audio&lt;/a> test instead.)&lt;/p></pre>
   <hr> <!-- SRC/SRCDOC PROCESSING MODEL -->
 
   <p>When an <code>iframe</code> element is <span data-x="insert an element into a document">inserted
-  into a document</span>, the user agent must create a <span>nested browsing context</span>, and
+  into a document</span> that has a <span>browsing context</span>, the user agent must create a <span>nested browsing context</span>, and
   then <span>process the <code>iframe</code> attributes</span> for the "first time".</p>
 
   <p>When an <code>iframe</code> element is <span data-x="remove an element from a document">removed
   from a document</span>, the user agent must <span data-x="a browsing context is
-  discarded">discard</span> the <span>nested browsing context</span>.</p>
+  discarded">discard</span> the <span>nested browsing context</span>, if any.</p>
 
   <p class="note">This happens without any <code data-x="event-unload">unload</code> events firing
   (the <span>nested browsing context</span> and its <code>Document</code> are <em><span data-x="a