Use a span instead of a dfn

source

@@ -89736,8 +89736,9 @@ dictionary <dfn>PromiseRejectionEventInit</dfn> : <span>EventInit</span> {
   <p>JavaScript contains an <span>implementation-defined</span> <span
   data-x="js-HostMakeJobCallback">HostMakeJobCallback</span>(<var>callable</var>) abstract operation
   to let hosts attach state to JavaScript callbacks that are called from inside <span
-  data-x="concept-task">task</span>s. HTML performs <dfn>incumbent settings object tracking in
-  Promises</dfn> by saving the <span>incumbent settings object</span> and a <span>JavaScript
+  data-x="concept-task">task</span>s. HTML <span
+  id="incumbent-settings-object-tracking-in-promises">tracks incumbent settings object in
+  Promises</span> by saving the <span>incumbent settings object</span> and a <span>JavaScript
   execution context</span> for the <span>active script</span>. User agents must use the following
   implementation: <ref spec=JAVASCRIPT></p>