| flo | WRAP Inflow IN Records Data |
| float | ARIA Server Float Data |
| flow | Microsoft Expression SketchFlow Data |
| flp | ActivInspire Flipchart |
| flp | Fractal Explorer Landscape Project |
| flr | WinFlash Results File |
| fls | Creator Fault List File |
| fls | WinFlash Flashcard Source |
| flt | Carlson 2016 Triangulated Irregular Network Data |
| flt | OpenFlight Model Data |
| flt | WinFlash Compiled Test |
| fltr | XTND Filter |
| flu | WinFlash Flashcard Source (new) |
| flw | Fluke LinkWare Database |
| flwa | Folder Lock Wallet File |
| flx | DataFlex Compiled Binary |
| flx | Flexstor Database |
| flx | MODTRAN FLX Output File |
| flxdato | OnScale Binary Results Data |
| flxext | OnScale Extrapolation Data |
| flxffl | OnScale Free Field Data |
| flxhst | OnScale Binary History Data |
| flxinp | OnScale Job Input Data |
| flxmdl | OnScale Binary Model Data |
| flxprt | OnScale Command Log Data |
| flxwrn | OnScale Warnings Data |
| flz | WinFlash Compiled Flashcard |
| fm | FileMaker Pro Data |
| fm5 | FileMaker Pro Data |
| fma | FMAudit Exported Audit Data |
| fma | PermitMD FMA Form Definition File |
| fma | PTV VISSIM Matrix Data |
| fmap | Family Atlas Published Family Map |
| fmc | FME Desktop Catalog Data |
| fmd | FARSITE Custom Fuel Model |
