| Abbreviation | Definition |
|---|---|
| FMIX | CCKX Incorporated |
| FMIX | Fairbanks Morse (CCKX Inc.) |
| FMLX | FMC Corporation |
| FMLX | FMC Corporation Inorganic Chemical Division |
| FMLX | FMC Corporation Inorganic Chemicals Division |
| FMOX | FMC Corporation |
| FMOX | FMC Corporation Inorganic Chemicals Division |
| FMRC | Farmrail Corporation |
| FNAX | Ferrellgas LLP |
| FNE | Ferrocarriles Nacionales de Mexico |
| FNE | TFM S. A. de C. V. |
| FNM | Ferrocarriles Nacionales de Mexico |
| FNOR | Florida Northern Railroad |
| FNOR | Florida Northern Railroad Company Inc |
| FOB | Free On Board |
| FOLU | Compact Container Systems |
| FOR | Fore River Railroad |
| FORPS | Fiber Optic Rail Pad Sensor |
| FORZ | Flexi-Van Leasing |
| FP | Fordyce and Princeton Railroad |