| Number | Octal Permission Representation | Ref |
| 0 | No permission | — |
| 1 | Execute permission | –x |
| 2 | Write permission | -w- |
| 3 | Execute and write permission: 1 (execute) + 2 (write) = 3 | -wx |
| 4 | Read permission | r– |
| 5 | Read and execute permission: 4 (read) + 1 (execute) = 5 | r-x |
| 6 | Read and write permission: 4 (read) + 2 (write) = 6 | rw- |
| 7 | All permissions: 4 (read) + 2 (write) + 1 (execute) = 7 | rwx |