Address comments

Add submit button check.

ought to be used*

Author: lukewarlow

source

@@ -56656,8 +56656,8 @@ interface <dfn interface>HTMLLegendElement</dfn> : <span>HTMLElement</span> {
 
   <p>Some form controls also have an <dfn data-x="concept-fe-optional-value">optional value</dfn>
   this largely mirrors the <span data-x="concept-fe-value">value</span> but doesn't normalize to an
-  empty string. <span class="note">This <!--non-normative-->should be used sparingly you generally
-  want <span data-x="concept-fe-value">value</span></span>.</p>
+  empty string. <span class="note">This ought to be used sparingly, you generally want <span
+  data-x="concept-fe-value">value</span></span>.</p>
 
   <p><code>input</code>, <code>textarea</code>, and <code>select</code> elements have a
   <dfn>user validity</dfn> boolean. It is initially set to false.</p>
@@ -60409,9 +60409,9 @@ fur
       </ol>
      </li>
 
-     <li><p>Otherwise, if <var>submitter</var> has an <span
-     data-x="concept-fe-optional-value">optional value</span>, then set <var>result</var> to that
-     <span data-x="concept-fe-optional-value">optional value</span>.</p></li>
+     <li><p>Otherwise, if <var>submitter</var> is a <span data-x="concept-submit-button">submit
+     button</span>, then set <var>result</var> to that <span
+     data-x="concept-fe-optional-value">optional value</span>.</p></li>
 
      <li><p><span>Close the dialog</span> <var>subject</var> with <var>result</var>.</p></li>