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Add "optional".

Co-Authored-By: Pierre-Antoine Champin <[email protected]>

Author: gkellogg

index.html

@@ -5863,7 +5863,7 @@ <h3>RemoteDocument</h3>
 
   <section class="changed">
     <h2>HTML Content Algorithms</h2>
-    <p class="note">This section describes features available
+    <p class="note">This section describes optional features available
       with a <a data-link-for="JsonLdOptions">documentLoader</a> supporting HTML script extraction.</p>
     <p>Implementations of a <a data-link-for="JsonLdOptions">documentLoader</a> MAY support extracting JSON-LD from
       <a data-cite="HTML/scripting.html#the-script-element">script elements</a> contained within an HTML [[HTML]] document.