SWIFT ISO 15022 - Code TRUS Financial acronyms The entire acronym collection of this site is now also available offline with this new app for iPhone and iPad. Meanings Trust: Beneficial owner is a trust. Trustee/Third Party: Financial instruments are held by a trustee, in third-party ownership. Usages Message type Field number Tag MT500 (Instruction to Register) 14 22F (Indicator) MT501 (Confirmation of Registration or Modification) 14 22F (Indicator) MT519 (Modification of Client Details) 13 22F (Indicator) MT574.W8BENO (IRS 1441 NRA-Form W8-BEN) 13 22F (Indicator: Type of Beneficial Owner)