| Abbreviation | Definition |
|---|---|
| FJ | Floyd Junior |
| FJ | Franz Joseph |
| FK | Felicity Kathleen |
| FK | Freddy Krueger |
| FL | Fat Larry |
| FLO | Florence |
| FLOB | Free Loading Oxygen Breather |
| FLORA | Florence |
| FML | First, Middle, and Last |
| FN | Frank Nathan |
| FOB | Friend Of Boyds |
| FOLE | Full Of Life Energetic |
| FP | Francois Paul |
| FP | Frank Paul |
| FR | Fernando Roberto |
| FR | Frederick Rex |
| Fran | Frances |
| Fran | Francis |
| FRANK | Francis |
| FRANK | Franklin |