Discussion history messages MUST be stamped with &xep0203; information qualified by the 'urn:xmpp:delay' namespace to indicate that they are sent with delayed delivery and to specify the times at which they were originally sent. (Note: The 'urn:xmpp:delay' namespace defined in XEP-0203 supersedes the older 'jabber:x:delay' namespace defined in &xep0091;; some implementations include both formats for backward compatibility.)
-In a non-anonymous room, the 'from' attribute of a discussion history message SHOULD be the full JID of the original sender. In a semi-anonymous room, the 'from' attribute MUST be set to the JID of the room itself.
+Discussion history messages MUST be stamped with &xep0203; information qualified by the 'urn:xmpp:delay' namespace to indicate that they are sent with delayed delivery and to specify the times at which they were originally sent. The 'from' attribute MUST be set to the JID of the room itself.
+(Note: The 'urn:xmpp:delay' namespace defined in XEP-0203 supersedes the older 'jabber:x:delay' namespace defined in &xep0091;; some implementations include both formats for backward compatibility.)
The service MUST send all discussion history messages before delivering the room subject and any "live" messages sent after the user enters the room.
@@ -1747,7 +1748,7 @@If there is no subject set, the room SHOULD return an empty &SUBJECT; element.
+If there is no subject set, the room MUST return an empty &SUBJECT; element.