diff --git a/source b/source
index 947d022212a..e5833bc48e9 100644
--- a/source
+++ b/source
@@ -3328,6 +3328,19 @@ a.setAttribute('href', 'https://example.com/'); // change the content attribute
      <li><dfn data-x="event-pointerup" data-x-href="https://w3c.github.io/pointerevents/#the-pointerup-event"><code>pointerup</code></dfn> event</li>
     </ul>
 
+    <p>The following features are defined in <cite>CSS Animations</cite>: <ref spec=CSSANIMATIONS></p>
+    <ul class="brief">
+     <li><dfn data-x="attr-onanimationend" data-x-href="https://drafts.csswg.org/css-animations-1/#dom-document-onanimationend"><code>onanimationend</code></dfn> attribute</li>
+     <li><dfn data-x="attr-onanimationiteration" data-x-href="https://drafts.csswg.org/css-animations-1/#dom-document-onanimationiteration"><code>onanimationiteration</code></dfn> attribute</li>
+     <li><dfn data-x="attr-onanimationstart" data-x-href="https://drafts.csswg.org/css-animations-1/#dom-document-onanimationstart"><code>onanimationstart</code></dfn> attribute</li>
+    </ul>
+
+    <p>The following features are defined in <cite>CSS Transitions</cite>: <ref spec=CSSTRANSITIONS></p>
+    <ul class="brief">
+     <li><dfn data-x="attr-ontransitionend" data-x-href="https://drafts.csswg.org/css-transitions-1/#event-handlers-on-elements-document-objects-and-window-objects"><code>ontransitionend</code></dfn> attribute</li>
+    </ul>
+
+
     <p>This specification sometimes uses the term <dfn data-x="">name</dfn> to refer to the event's
     <span data-x="concept-event-type">type</span>; as in, "an event named <code
     data-x="">click</code>" or "if the event name is <code data-x="">keypress</code>". The terms
@@ -117838,6 +117851,12 @@ if (s = prompt('What is your name?')) {
    <dd><p>Use script to handle the <code data-x="event-dnd-dragenter">dragenter</code> and <code
    data-x="event-dnd-dragover">dragover</code> events instead.</p></dd>
 
+   <dt><dfn><code data-x="attr-onwebkitanimationend">onwebkitanimationend</code></dfn> on all elements</dt>
+   <dt><dfn><code data-x="attr-onwebkitanimationiteration">onwebkitanimationiteration</code></dfn> on all elements</dt>
+   <dt><dfn><code data-x="attr-onwebkitanimationstart">onwebkitanimationstart</code></dfn> on all elements</dt>
+   <dt><dfn><code data-x="attr-onwebkittransitionend">onwebkittransitionend</code></dfn> on all elements</dt>
+   <dd><p>Use the unprefixed variants instead: <code data-x="attr-onanimationend">onanimationend</code>, <code data-x="attr-onanimationiteration">onanimationiteration</code>, <code data-x="attr-onanimationstart">onanimationstart</code>, and <code data-x="attr-ontransitionend">ontransitionend</code>.
+
    <dt><dfn><code data-x="attr-body-alink">alink</code></dfn> on <code>body</code> elements</dt>
    <dt><dfn><code data-x="attr-body-bgcolor">bgcolor</code></dfn> on <code>body</code> elements</dt>
    <dt><dfn><code data-x="attr-body-bottommargin">bottommargin</code></dfn> on <code>body</code> elements</dt>
@@ -124392,7 +124411,7 @@ INSERT INTERFACES HERE
    <dd><cite><a href="https://drafts.csswg.org/css-sizing/">CSS Intrinsic &amp; Extrinsic Sizing Module</a></cite>, T. Atkins, E. Etemad. W3C.</dd>
 
    <dt id="refsCSSTRANSITIONS">[CSSTRANSITIONS]</dt>
-   <dd>(Non-normative) <cite><a href="https://drafts.csswg.org/css-transitions/">CSS Transitions</a></cite>, D. Jackson, D. Hyatt, C. Marrin, L. Baron. W3C.</dd>
+   <dd><cite><a href="https://drafts.csswg.org/css-transitions/">CSS Transitions</a></cite>, D. Jackson, D. Hyatt, C. Marrin, L. Baron. W3C.</dd>
 
    <dt id="refsCSSUI">[CSSUI]</dt>
    <dd><cite><a href="https://drafts.csswg.org/css-ui/">CSS3 Basic User Interface Module</a></cite>, T. &Ccedil;elik. W3C.</dd>