Mandatory
This field contains the collection number of the remitting bank.
If the reference cannot be contained in this field, the code 'SEE72' may be used and the reference placed in field 72.
This field must not start or end with a slash '/' and must not contain two consecutive slashes '//' (Error code(s): T26).
If the MT 412 is sent to advise acceptance of a previously received MT 405 Clean Collection, then:
field 21 of the MT 412 should contain the transaction reference of this MT 405, ie, field 21A of sequence B, and;
field 72 of the MT 412 should contain the Sender's reference of this MT 405, ie, field 20 of sequence A.