| Code | Display | Definition |
| C | completion | Respond with exceptions and a notification of completion |
| D | detail | Respond with exceptions, completion, modifications and include more detail information (if applicable) |
| E | exception | Respond with exceptions only |
| F | confirmation | Respond with exceptions, completion, and modification with detail (as above), and send positive confirmations even if no modifications are being made. |
| N | message-control | Respond only with message level acknowledgements, i.e., only notify acceptance or rejection of the message, do not include any application-level detail |
| R | modification | Respond with exceptions, completions and modifications or revisions done before completion |
| X | none | Do not send any kind of response |