This message is used to communicate early settlement information to a custodian or clearing agent.
It may be considered a definitive settlement instruction, where an agreement to this effect exists between a custodian or clearing agent and its client.
This message may also be used to:
request the cancellation of a settlement instruction previously sent
re-send a settlement instruction previously sent
provide a third party with a copy of the message (be it the settlement instruction or request for cancellation) being sent.