| Abbreviation | Definition |
|---|---|
| MMGE2 | chinist's Mate (aviation Bombing) Petty Officer Second Class |
| MMGE2 | Machinist's Mate (aviation Bombing) Petty Officer Second Class |
| MMGFA | chinist's Mate (gas Generating) Fireman Apprentice |
| MMGFA | Machinist's Mate (gas Generating) Fireman Apprentice |
| MMGFN | chinist's Mate (gas Generating) Fireman |
| MMGFN | Machinist's Mate (gas Generating) Fireman |
| MMGFR | chinist's Mate (gas Generating) Fireman Recruit |
| MMGFR | Machinist's Mate (gas Generating) Fireman Recruit |
| MMKR | Boilermaker |
| MMKR | ilermaker |
| MML1 | chinist's Mate (general) Petty Officer 1st Class |
| MML1 | Machinist's Mate (general) Petty Officer 1st Class |
| MML2 | chinist's Mate (general) Petty Officer 2nd Class |
| MML2 | Machinist's Mate (general) Petty Officer 2nd Class |
| MML3 | chinist's Mate (general) Petty Officer 3rd Class |
| MML3 | Machinist's Mate (general) Petty Officer 3rd Class |
| MMLC | chinist's Mate (general) Chief Petty Officer |
| MMLC | Machinist's Mate (general) Chief Petty Officer |
| MMLFA | chinist's Mate (general) Fireman Apprentice |
| MMLFA | Machinist's Mate (general) Fireman Apprentice |