| 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 |
| fmdb | Ensoft Formulator Object Database |
| fmedb | Foto-Mosaik-Edda Mosaic Database |
| fmelic | FME License |
| fmf | FME Desktop Metafile |
| fmh | Family Medical History HD Data |
| fmi | FME Include File |
| fmk4 | FileMaker Pro for Mac Data |
| fml | OFML Scene Data |
| fmm | FreeMind MindMap |
| fmod | Adobe Illustrator Flattening Module |
| fmp | FileMaker Pro Data |
