| Abbreviation | Definition |
|---|---|
| MEWFA | Metalsmith (welder) Fireman Apprentice |
| MEWFA | talsmith (welder) Fireman Apprentice |
| MEWFN | Metalsmith (welder) Fireman |
| MEWFN | talsmith (welder) Fireman |
| MEWFR | Metalsmith (welder) Fireman Recruit |
| MEWFR | talsmith (welder) Fireman Recruit |
| MIDN | dshipman |
| MIDN | Midshipman |
| MJC | Military junior colleges |
| ML1 | lder 1st Class Petty Officer |
| ML1 | Molder 1st Class Petty Officer |
| ML2 | lder 2nd Class Petty Officer |
| ML2 | Molder 2nd Class Petty Officer |
| ML3 | lder 3rd Class Petty Officer |
| ML3 | Molder 3rd Class Petty Officer |
| MLC | lder Chief Petty Officer |
| MLC | Molder Chief Petty Officer |
| MLCM | lder Master Chief Petty Officer |
| MLCM | Molder Master Chief Petty Officer |
| MLCS | lder Senior Chief Petty Officer |