A code indicating acknowledgement, or rejection (the action taken) of a subject interchange, or part of the subject interchange, or indication of interchange receipt.
This level and all lower levels rejected
The corresponding referenced-level and all its lower referenced-levels are rejected. One or more errors are reported at this reporting-level or a lower reporting-level.
This level acknowledged and all lower levels acknowledged if not explicitly rejected
The corresponding referenced-level is acknowledged. All messages, packages, or groups at the lower referenced-levels are acknowledged except those explicitly reported as rejected at their reporting-level in this CONTRL message.