| Abbreviation | Definition |
|---|---|
| FEMX | Freight Equipment Management |
| FEPX | FirstEnergy Corp |
| FESHP | Fort Erie, Snake Hill, & Pacific Railway |
| FEXZ | Florida Express Carriers |
| FFEZ | Frozen Food Express |
| FFFZ | Flexi-Van Leasing |
| FFFZ | Flexi-Van Leasing Incorporated |
| FFGC | FFG&C Railroad |
| FFIX | Finlay Forest Industries (Procor) |
| FFIX | Procor Limited |
| FFTX | Fun Trains Inc. |
| FFTX | Fun Trains Incorporated |
| FG | French Gauge |
| FGCX | Florida Gulf Coast Railroad Museum |
| FGER | Fruit Growers Express |
| FGER | Fruit Growers Express Company |
| FGEX | Fruit Growers Express |
| FGGX | Farmers Grain Cooperative |
| FGGX | Farmers Grain Co-Operative |
| FGLK | Finger Lakes Railway |