SWIFT ISO 15022 - Code NTBK Meaning Not to Book: Certificate/title should not be booked in the shareholder account with the company and should be sent to the depository bank. 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)