AK2 Transaction Set Response Header
To start acknowledgment of a single transaction set
Code uniquely identifying a Transaction Set
AK201 is the transaction set ID found in the ST segment (ST01) in the transaction set being acknowledged.
Identifying control number that must be unique within the transaction set functional group assigned by the originator for a transaction set
AK202 is the transaction set control number found in the ST segment in the transaction set being acknowledged.