| 1 | OK response |
| No further information. |
| 2 | Syntax error |
| Error detected in syntax. |
| 3 | Invalid header |
| Invalid header segment received. |
| 4 | Invalid trailer segment |
| Invalid trailer segment received. |
| 5 | Unsupported syntax |
| Syntax version/release not supported. |
| 6 | Unsupported scenario type |
| Scenario type not supported. |
| 7 | Unsupported scenario version |
| Scenario version/release not supported. |
| 8 | Unsupported dialogue type |
| Dialogue type not supported for this scenario. |
| 9 | Unsupported dialogue version |
| Dialogue type version/release not supported. |
| 10 | Unauthorised sender |
| Sender not authorised. |
| 11 | Sender rejected |
| Sender rejected for administrative reasons. |
| 12 | Multiple transactions unsupported |
| Multiple parallel transactions not supported. |
| 13 | Multiple dialogues unsupported |
| Multiple parallel dialogues not supported. |
| 14 | Resources unavailable |
| Resources unavailable for requested function. |
| 15 | Unknown transaction |
| Referenced transaction does not exist. |
| 16 | Unknown dialogue |
| Referenced dialogue does not exist. |
| 17 | Invalid function |
| Function invalid for current dialogue state. |
| 18 | Service unavailable |
| Requested service is unavailable. |
| 19 | Application unavailable |
| Requested application not available. |
| 20 | Time-out |
| Response not received within expected time. |
| 21 | Unable to process interactively |
| To notify the initiator that a specific request cannot be processed interactively. |
| 22 | Correctable application error |
| To notify the initiator that an application error, that is correctable by the initiator, was made in the request message. |
| 23 | Nothing to return |
| To notify the initiator that there is no information to return in response to an inquiry. |
| 24 | Data not accessible |
| To notify the initiator that the requested information cannot be returned. |
| 25 | Non-correctable application error |
| To notify the initiator that some type of system or processing error was encountered, not related to the data received. |
