diff --git a/source b/source
index 1f4439d93a2..50b6a4f4f75 100644
--- a/source
+++ b/source
@@ -9009,8 +9009,7 @@ o.myself = o;</code></pre>
   <p>When a <code>Document</code> is created by a <span data-x="concept-script">script</span> using
   the <code data-x="dom-DOMImplementation-createDocument">createDocument()</code> or <code
   data-x="dom-DOMImplementation-createHTMLDocument">createHTMLDocument()</code> the
-  <code>Document</code> is both <span>ready for post-load tasks</span> and <span>completely
-  loaded</span> immediately.</p>
+  <code>Document</code> is <span>ready for post-load tasks</span> immediately.</p>
 
   <p><dfn data-export="">The document's referrer</dfn> is a string (representing a <span>URL</span>)
   that can be set when the <code>Document</code> is created. If it is not explicitly set, then its
@@ -14595,8 +14594,8 @@ people expect to have work and what is necessary.
         the <em>later</em> of the following two conditions occurs:</p>
 
         <ul>
-         <li>At least <var>time</var> seconds have elapsed since <var>document</var> has
-         <span>completely loaded</span>, adjusted to take into account user or user agent
+         <li>At least <var>time</var> seconds have elapsed since <var>document</var>'s
+         <span>completely loaded time</span>, adjusted to take into account user or user agent
          preferences.</li>
          <!-- https://software.hixie.ch/utilities/js/live-dom-viewer/?saved=774 -->
 
@@ -30043,13 +30042,8 @@ interface <dfn>HTMLIFrameElement</dfn> : <span>HTMLElement</span> {
     </ol>
    </li>
 
-   <li><p>Otherwise, if <var>element</var> has no <code data-x="attr-iframe-src">src</code>
-   attribute specified, and <var>initialInsertion</var> is true, then <span>queue an element
-   task</span> on the <span>DOM manipulation task source</span> given <var>element</var> and the
-   <span>iframe load event steps</span>.</p></li>
-
-   <li><p>Otherwise, run the <span>otherwise steps for <code>iframe</code> or <code>frame</code>
-   elements</span> given <var>element</var>.</p></li>
+   <li><p>Otherwise, if <var>initialInsertion</var> is false, run the <span>otherwise steps for
+   <code>iframe</code> or <code>frame</code> elements</span> given <var>element</var>.</p></li>
   </ol>
 
   <p>The <dfn>otherwise steps for <code>iframe</code> or <code>frame</code> elements</dfn>, given an
@@ -30135,9 +30129,6 @@ interface <dfn>HTMLIFrameElement</dfn> : <span>HTMLElement</span> {
 
   <!-- see also the note near similar text for the location.assign() method -->
 
-  <p>When a <code>Document</code> in an <code>iframe</code> is marked as <span>completely
-  loaded</span>, the user agent must run the <span>iframe load event steps</span>.</p>
-
   <p class="note">A <code data-x="event-load">load</code> event is also fired at the
   <code>iframe</code> element when it is created if no other data is loaded in it.</p>
 
@@ -30145,24 +30136,24 @@ interface <dfn>HTMLIFrameElement</dfn> : <span>HTMLElement</span> {
   iframe load</dfn> flag. When a <code>Document</code> is created, these flags must be unset for
   that <code>Document</code>.</p>
 
-  <p>The <dfn>iframe load event steps</dfn> are as follows:</p>
+  <p>To run the <dfn>iframe load event steps</dfn>, given an <code>iframe</code> element
+  <var>element</var>:</p>
 
   <ol>
-   <li><p>Let <var>child document</var> be the <span>active document</span> of the
-   <code>iframe</code> element's <span>nested browsing context</span> (which cannot be null at this
-   point).</p></li>
+   <li><p>Assert: <var>element</var>'s <span>nested browsing context</span> is not null.</p></li>
 
-   <li><p>If <var>child document</var> has its <span>mute iframe load</span> flag set,
+   <li><p>Let <var>childDocument</var> be the <span>active document</span> of <var>element</var>'s
+   <span>nested browsing context</span>.</p></li>
+
+   <li><p>If <var>childDocument</var> has its <span>mute iframe load</span> flag set, then
    return.</p></li>
 
-   <li><p>Set <var>child document</var>'s <span>iframe load in progress</span>
-   flag.</p></li>
+   <li><p>Set <var>childDocument</var>'s <span>iframe load in progress</span> flag.</p></li>
 
    <li><p><span data-x="concept-event-fire">Fire an event</span> named <code
-   data-x="event-load">load</code> at the <code>iframe</code> element.</p></li>
+   data-x="event-load">load</code> at <var>element</var>.</p></li>
 
-   <li><p>Unset <var>child document</var>'s <span>iframe load in progress</span>
-   flag.</p></li>
+   <li><p>Unset <var>childDocument</var>'s <span>iframe load in progress</span> flag.</p></li>
   </ol>
 
   <p class="warning">This, in conjunction with scripting, can be used to probe the URL space of the
@@ -30799,12 +30790,6 @@ interface <dfn>HTMLEmbedElement</dfn> : <span>HTMLElement</span> {
 
            <li><p><var>element</var> now <span>represents</span> its <span>nested browsing
            context</span>.</p></li>
-
-           <li><p>When the <code>Document</code> of <var>element</var>'s <span>nested browsing
-           context</span> is marked as <span>completely loaded</span>, <span>queue an element
-           task</span> on the <span>DOM manipulation task source</span> given <var>element</var> to
-           <span data-x="concept-event-fire">fire an event</span> named <code
-           data-x="event-load">load</code> at <var>element</var>.</p></li>
           </ol>
          </dd>
 
@@ -31485,14 +31470,6 @@ interface <dfn>HTMLObjectElement</dfn> : <span>HTMLElement</span> {
         data-x="attr-object-data">data</code> attribute of the <code>object</code> element doesn't
         get updated if the browsing context gets further navigated to other locations.)</p>
 
-        <p>If the <span>URL</span> of the given resource <em>is</em> <code>about:blank</code>, then,
-        instead, the user agent must <span>queue an element task</span> on the <span>DOM
-        manipulation task source</span> given the <code>object</code> element to <span
-        data-x="concept-event-fire">fire an event</span> named <code data-x="event-load">load</code>
-        at the <code>object</code> element. <span class="note">No <code
-        data-x="event-load">load</code> event is fired at the <code>about:blank</code> document
-        itself.</span></p>
-
         <p>The <code>object</code> element <span>represents</span> its <span>nested browsing
         context</span>.</p>
 
@@ -31544,11 +31521,18 @@ interface <dfn>HTMLObjectElement</dfn> : <span>HTMLElement</span> {
      represents.</p>
 
      <li>
-      <p>Return. Once the resource is completely loaded, <span>queue an element task</span> on the
-      <span>DOM manipulation task source</span> given the <code>object</code> element to <span
-      data-x="concept-event-fire">fire an event</span> named <code data-x="event-load">load</code>
-      at the element.</p>
+      <p>If the <code>object</code> element does not represent its <span>nested browsing
+      context</span>, then once the resource is completely loaded, <span>queue an element
+      task</span> on the <span>DOM manipulation task source</span> given the <code>object</code>
+      element to <span data-x="concept-event-fire">fire an event</span> named <code
+      data-x="event-load">load</code> at the element.</p>
+
+      <p class="note">If the element <em>does</em> represent its <span>nested browsing
+      context</span>, then an analogous task will be queued when the created <code>Document</code>
+      is <span data-x="completely finish loading">completely finished loading</span>.</p>
      </li>
+
+     <li><p>Return.</p></li>
     </ol>
    </li>
 
@@ -76935,8 +76919,8 @@ popup4.close();</code></pre></div>
    <span>origin</span> is <var>origin</var>, <span>active sandboxing flag set</span> is
    <var>sandboxFlags</var>, <span data-x="concept-document-permissions-policy">permissions
    policy</span> is <var>permissionsPolicy</var>, <span data-x="concept-document-coop">cross-origin
-   opener policy</span> is <var>coop</var>, and which is both <span>ready for post-load tasks</span>
-   and <span>completely loaded</span> immediately.</p></li>
+   opener policy</span> is <var>coop</var>, and which is <span>ready for post-load
+   tasks</span>.</p></li>
 
    <li><p>Ensure that <var>document</var> has a single child <code>html</code> node, which itself
    has two empty child nodes: a <code>head</code> element, and a <code>body</code> element.</p></li>
@@ -76959,6 +76943,8 @@ popup4.close();</code></pre></div>
    <li><p>Add <var>document</var> to <var>browsingContext</var>'s <span>session
    history</span>.</p></li>
 
+   <li><p><span>Completely finish loading</span> <var>document</var>.</p></li>
+
    <li><p>Return <var>browsingContext</var>.</p></li>
   </ol>
 
@@ -84512,9 +84498,38 @@ dictionary <dfn>PageTransitionEventInit</dfn> : <span>EventInit</span> {
   <p>The <dfn><code data-x="dom-PageTransitionEvent-persisted">persisted</code></dfn> attribute must
   return the value it was initialized to. It represents the context information for the event.</p>
 
-  </div>
+  <h4>Loading documents</h4>
 
+  <p>A <code>Document</code> has a <dfn>completely loaded time</dfn> (a time or null), which is
+  initially null.</p>
 
+  <p>A <code>Document</code> is considered <dfn>completely loaded</dfn> if its <span>completely
+  loaded time</span> is non-null.
+
+  <p>To <dfn>completely finish loading</dfn> a <code>Document</code> <var>document</var>:</p>
+
+  <ol>
+   <li><p>Assert: <var>document</var>'s <span data-x="concept-document-bc">browsing context</span>
+   is non-null.</p></li>
+
+   <li><p>Set <var>document</var>'s <span>completely loaded time</span> to the current
+   time.</p></li>
+
+   <li><p>Let <var>container</var> be <var>document</var>'s <span
+   data-x="concept-document-bc">browsing context</span>'s <span
+   data-x="bc-container">container</span>.</p></li>
+
+   <li><p>If <var>container</var> is an <code>iframe</code> element, then <span>queue an element
+   task</span> on the <span>DOM manipulation task source</span> given <var>container</var> to run
+   the <span>iframe load event steps</span> given <var>container</var>.</p></li>
+
+   <li><p>Otherwise, if <var>container</var> is non-null, then <span>queue an element task</span> on
+   the <span>DOM manipulation task source</span> given <var>container</var> to <span
+   data-x="concept-event-fire">fire an event</span> named <code data-x="event-load">load</code> at
+   <var>container</var>.</p>
+  </ol>
+
+  </div>
 
   <h4>Unloading documents</h4>
 
@@ -110790,9 +110805,7 @@ document.body.appendChild(text);
 
    <li><p>The <code>Document</code> is now <dfn>ready for post-load tasks</dfn>.</p></li>
 
-   <li><p><span>Queue a global task</span> on the <span>DOM manipulation task source</span> given
-   the <code>Document</code>'s <span>relevant global object</span> to mark the <code>Document</code>
-   as <dfn>completely loaded</dfn>.</p></li>
+   <li><p><span>Completely finish loading</span> the <code>Document</code>.</p></li>
   </ol>
 
   <p>When the user agent is to <dfn>abort a parser</dfn>, it must run the following steps:</p>
@@ -115733,22 +115746,12 @@ interface <dfn>HTMLFrameSetElement</dfn> : <span>HTMLElement</span> {
   data-x="process-frame-initial-insertion"><var>initialInsertion</var></dfn>:</p>
 
   <ol>
-   <li><p>If <var>element</var> has no <code undefined data-x="attr-frame-src">src</code> attribute
-   specified, and <var>initialInsertion</var> is true, then <span>queue an element task</span> on
-   the <span>DOM manipulation task source</span> given <var>element</var> to <span
-   data-x="concept-event-fire">fire an event</span> named <code data-x="event-load">load</code> at
-   <var>element</var>.</p></li>
+   <li><p>If <var>initialInsertion</var> is true, then do nothing.</p></li>
 
    <li><p>Otherwise, run the <span>otherwise steps for <code>iframe</code> or <code>frame</code>
    elements</span> given <var>element</var>.</p></li>
   </ol>
 
-  <!-- next few paragraphs are also from <iframe> but less detailed -->
-
-  <p>When a <code>Document</code> in a <code>frame</code> is marked as <span>completely
-  loaded</span>, the user agent must <span data-x="concept-event-fire">fire an event</span> named
-  <code data-x="event-load">load</code> at the <code>frame</code> element.</p>
-
   <p>The <code>frame</code> element <span>potentially delays the load event</span>.</p>
 
   <!-- END of section that's very similar to <iframe> -->