| Abbreviation | Definition |
|---|---|
| IMISA | Instrumentman (instrument Repairman) Seaman Apprentice |
| IMISA | strumentman (instrument Repairman) Seaman Apprentice |
| IMISN | Instrumentman (instrument Repairman) Seaman |
| IMISN | strumentman (instrument Repairman) Seaman |
| IMISR | Instrumentman (instrument Repairman) Seaman Recruit |
| IMISR | strumentman (instrument Repairman) Seaman Recruit |
| IMO | Intrepid Marine Observer |
| IMO1 | Instrumentman (office Machine Repairman) Petty Officer 1st Class |
| IMO1 | nstrumentman (office Machine Repairman) Petty Officer 1st Class |
| IMO2 | Instrumentman (office Machine Repairman) Petty Officer 2nd Class |
| IMO2 | nstrumentman (office Machine Repairman) Petty Officer 2nd Class |
| IMO3 | Instrumentman (office Machine Repairman) Petty Officer 3rd Class |
| IMO3 | nstrumentman (office Machine Repairman) Petty Officer 3rd Class |
| IMOC | Instrumentman (office Machine Repairman) Chief Petty Officer |
| IMOC | nstrumentman (office Machine Repairman) Chief Petty Officer |
| IMOSA | Instrumentman (office Machine Repairman) Seaman Apprentice |
| IMOSA | nstrumentman (office Machine Repairman) Seaman Apprentice |
| IMOSN | Instrumentman (office Machine Repairman) Seaman |
| IMOSN | nstrumentman (office Machine Repairman) Seaman |
| IMOSR | Instrumentman (office Machine Repairman) Seaman Recruit |