| 1 | Information |
| Non Error information, e.g. acknowledgement that party is still operational. |
| 2 | Warning |
| Warning, e.g. resources getting low. |
| 3 | Non-fatal error |
| Non-fatal error detected by party sending the UIR. Dialogue integrity may be compromised. |
| 4 | Abort dialogue |
| Established dialogue cannot continue. |
| 5 | Query status |
| Request for a status report from other party. Should be answered with a 'Status report' (see code value '6' below). |
| 6 | Status report |
| Reporting status of dialogue as perceived by sending party. |
| 7 | Pause dialogue |
| Advise other party to stop transferring data within this dialogue until a 'Continue dialogue' is received. |
| 8 | Continue dialogue |
| Advise that data flow may continue after being 'Paused' (see code value '7' above). |
| 9 | Start dialogue reject |
| Dialogue cannot be initiated. |