| Abbreviation | Definition |
|---|---|
| IM1 | Instrumentman Petty Officer 1st Class |
| IM1 | strumentman Petty Officer 1st Class |
| IM2 | Instrumentman Petty Officer 2nd Class |
| IM2 | strumentman Petty Officer 2nd Class |
| IM3 | Instrumentman Petty Officer 3rd Class |
| IM3 | strumentman Petty Officer 3rd Class |
| IMC | Instrumentman Chief Petty Officer |
| IMC | strumentman Chief Petty Officer |
| IMCM | Instrumentman Master Chief Petty Officer |
| IMCM | strumentman Master Chief Petty Officer |
| IMCS | Instrumentman Senior Chief Petty Officer |
| IMCS | strumentman Senior Chief Petty Officer |
| IMI1 | Instrumentman (instrument Repairman) Petty Officer 1st Class |
| IMI1 | strumentman (instrument Repairman) Petty Officer 1st Class |
| IMI2 | Instrumentman (instrument Repairman) Petty Officer 2nd Class |
| IMI2 | strumentman (instrument Repairman) Petty Officer 2nd Class |
| IMI3 | Instrumentman (instrument Repairman) Petty Officer 3rd Class |
| IMI3 | strumentman (instrument Repairman) Petty Officer 3rd Class |
| IMIC | Instrumentman (instrument Repairman) Chief Petty Officer |
| IMIC | strumentman (instrument Repairman) Chief Petty Officer |