Mandatory
This field identifies the function of the message.
Function must contain one of the following codes (Error code(s): T86):
Subfunction, when present, must contain one of the following codes (Error code(s): T85):
To cancel a previously sent message, Function is CANC. The reference in the linkages sequence must contain the Sender's reference of the message to be cancelled. A copy of at least the mandatory fields of the message to be cancelled must be present; optional fields do not need to be present for SWIFT validation.