diff --git a/source b/source
index 093339b50c2..eabff7fbbb7 100644
--- a/source
+++ b/source
@@ -60154,6 +60154,9 @@ interface <dfn interface>HTMLDetailsElement</dfn> : <span>HTMLElement</span> {
    <var>insertedNode</var>.</p></li>
   </ol>
 
+  <p class="note">To be clear, these attribute change and insertion steps also run when an attribute
+  or element is inserted via the parser.</p>
+
   <p>To <dfn>queue a details toggle event task</dfn> given a <code>details</code> element
   <var>element</var>, a string <var>oldState</var>, and a string <var>newState</var>: