This field contains the reference to the original message to which this query relates.
This field must not start or end with a slash '/' and must not contain two consecutive slashes '//'.
If the query is related to a SWIFT message, this field must contain the content of field 20 Transaction Reference Number from the original message.
If the query is related to a non-SWIFT message, this field must contain an equivalent reference to the original message.
Alternatively, if the query is a nostro enquiry of a single transaction contained in a previous MT 950 or equivalent, the account servicing institution's reference as taken from subfield 8 of field 61 may be used. Where more than one transaction contained in the statement or the entire statement is being queried, the field 20 Transaction Reference Number or equivalent of the original statement should be used.