HP-UX
| ID | Description |
|---|---|
| 0 | System halted |
| S | Single-User mode, booted to system console only, with only root filesystem mounted (as read-only) |
| s | Single-User mode, identical to S except the current terminal acts as the system console |
| 1 | Single-User mode with local filesystems mounted (read-write) |
| 2 | Multi-User mode with most daemons started and Common Desktop Environment launched |
| 3 | Identical to runlevel 2 with NFS exported |
| 4 | Multi-User mode with VUE started instead of CDE |
| 5, 6 | Not used/User-definable |