| Abbreviation | Definition |
|---|---|
| FISZ | Ecorail Incorporated |
| FJG | Fonda, Johnstown and Gloversville Railroad |
| FJLX | Big West Oil Company |
| FJLX | F.J. Lewis Petroleum (Big West Oil) |
| FL | Family Lines System |
| FLAX | Flexsys America |
| FLAX | Flexsys America L. P. |
| FLAZ | Flexi-Van Leasing |
| FLCX | Flex Leasing Corporation |
| FLDU | Feld Entertainment |
| FLDX | Fieldston Transportation Services (DTE Transportation Services) |
| FLDX | Fieldston Transportation Services LLC |
| FLEX | RailLease Inc. |
| FLEX | RailLease Incorporated |
| FLGZ | Flexi-Van Leasing |
| FLIX | Farmland Industries |
| FLIX | Farmland Industries Incorporated |
| FLJX | Big West Oil Company |
| FLJX | F.J. Lewis Petroleum (Big West Oil) |
| FLNX | R. P. Flynn (Ohio Railway Supply) |