diff --git a/xep-0100.xml b/xep-0100.xml
index 308975b1..42053425 100644
--- a/xep-0100.xml
+++ b/xep-0100.xml
@@ -249,6 +249,7 @@
   </query>
 </iq>
           ]]></example>
+          <p>Note: The XML character data of the &lt;username/&gt; element SHOULD be the Jabber User's LegacyUserAddress as described under <link url='#addressing'>Addressing</link>, such as an AOL screen name, ICQ number, Windows Live Messenger (formerly MSN Messenger) address, or Yahoo! ID.</p>
         </li>
         <li>
           <p>Gateway verifies that registration information provided by Jabber User is valid (using whatever means appropriate for the Legacy Service) and informs Jabber User of success [A1].</p>