SWIFT ISO 15022 - Code OUTS Financial acronyms The entire acronym collection of this site is now also available offline with this new app for iPhone and iPad. Meaning Outstanding Trade: SSI update is effective for all trades settling on and after effective date irrespective of trade date. Usages Message type Field number Tag MT670 (Standing Settlement Instruction Update Notification Request) 21 22F (Indicator) MT671 (Standing Settlement Instruction Update Notification) 16 22F (Indicator)