| Code | Description | Repr |
|---|
| 0001 | Syntax identifier | a4 |
| 0002 | Syntax version number | n1 |
| 0007 | Partner identification code qualifier | an..4 |
| 0013 | Service segment tag, coded | a3 |
| 0025 | Recipient's reference/password qualifier | an2 |
| 0029 | Processing priority code | a1 |
| 0031 | Acknowledgement request | n1 |
| 0035 | Test indicator | n1 |
| 0051 | Controlling agency | an..2 |
| 0052 | Message version number | an..3 |
 | 0054 | Message release number | an..3 |
| 0065 | Message type identifier | an..6 |
| 0073 | First/last sequence message transfer indication | a1 |
| 0081 | Section identification | a1 |
| 0083 | Action, coded | an..3 |
| 0085 | Syntax error, coded | an..3 |
