| Abbreviation | Definition |
|---|---|
| IMOSR | nstrumentman (office Machine Repairman) Seaman Recruit |
| IMSA | Instrumentman Seaman Apprentice |
| IMSA | strumentman Seaman Apprentice |
| IMSN | Instrumentman Seaman |
| IMSN | strumentman Seaman |
| IMSR | Instrumentman Seaman Recruit |
| IMSR | strumentman Seaman Recruit |
| IMW1 | Instrumentman (watch & Clock Repairman) Petty Officer 1st Class |
| IMW1 | nstrumentman (watch & Clock Repairman) Petty Officer 1st Class |
| IMW2 | Instrumentman (watch & Clock Repairman) Petty Officer 2nd Class |
| IMW2 | nstrumentman (watch & Clock Repairman) Petty Officer 2nd Class |
| IMW3 | Instrumentman (watch Repair) Petty Officer Third Class |
| IMW3 | strumentman (watch Repair) Petty Officer Third Class |
| IMWC | Instrumentman (watch & Clock Repairman) Chief Petty Officer |
| IMWC | nstrumentman (watch & Clock Repairman) Chief Petty Officer |
| IMWSA | Instrumentman (watch & Clock Repairman) Seaman Apprentice |
| IMWSA | nstrumentman (watch & Clock Repairman) Seaman Apprentice |
| IMWSN | Instrumentman (watch & Clock Repairman) Seaman |
| IMWSN | nstrumentman (watch & Clock Repairman) Seaman |
| IMWSR | Instrumentman (watch & Clock Repairman) Seaman Recruit |