| Abbreviation | Definition |
|---|---|
| FCU1 | re Controlman (underwater Weapons) |
| FCU2 | Fire Controlman (underwater Weapons) |
| FCU2 | re Controlman (underwater Weapons) |
| FCU3 | Fire Controlman (underwater Weapons) |
| FCU3 | re Controlman (underwater Weapons) |
| FCUC | Fire Controlman (underwater Weapons) Chief Petty Officer |
| FCUC | re Controlman (underwater Weapons) Chief Petty Officer |
| FCUSA | Fire Controlman (underwater Weapons) Seaman Apprentice |
| FCUSA | re Controlman (underwater Weapons) Seaman Apprentice |
| FCUSN | Fire Controlman (underwater Weapons) Seaman |
| FCUSN | re Controlman (underwater Weapons) Seaman |
| FCUSR | Fire Controlman (underwater Weapons) Seaman Recruit |
| FCUSR | re Controlman (underwater Weapons) Seaman Recruit |
| FDC | Fire Direction Control |
| FDNF | Forward Deployed Naval Forces |
| FFR | Fleet and Family Readiness |
| FN | Fireman |
| FN | reman |
| FNC | Future Naval Capabilities |
| FNCS | Full Naval Control of Shipping |