Clear up confusion about subsequent corrections and ids (it's the payloads getting replaced, not the message identity).
A single message may be corrected multiple times by subsequent edits.
A correction MUST only be allowed when both the original message and correction originate from the same sender
While it's not possible to prevent this protocol from being used in such a way, it is not intended that it provides a way to continue expanding a previous message indefinitely and clients, in as much as it is sensible, should present use of this extension only for correction rather than for providing a continuous stream, for which &xep0301; can be used instead.
-Correction MUST only be used to change the details of a stanza (e.g. the message body) and not to change the nature of the stanza (e.g. correction MUST NOT be used to turn a chat message into a pubsub notification)
+If the same message is to be corrected several times, the id of the original message is used in each case (e.g. If a message of id 1 is corrected by a message of id 2, a subsequent correction should correct 1, not 2).
+Correction MUST only be used to change the logical content details of a stanza (e.g. the message body) and not to change the nature of the stanza or its metadata (e.g. correction MUST NOT be used to turn a chat message into a pubsub notification). Where a correction stanza includes metadata, for example stanza or MAM ids, these are properties of the correction stanza, and do not correct aspects of the original stanza.
While it is possible to use this protocol to correct messages older than the most recent received from a full JID, such use is out of scope for this document and support for this SHOULD NOT be assumed without further negotiation.