| Extension | File Description |
| .FILEPLANET | Uncommon Files |
| .FILES | Uncommon Files |
| .FILM | Uncommon Files |
| .FILMAO | Uncommon Files |
| .FILTER | Uncommon Files |
| .FIM | Uncommon Files |
| .FIN | Uncommon Files |
| .FINAL | Uncommon Files |
| .FIND | Uncommon Files |
| .FINDER | Uncommon Files |
| .FIO | Uncommon Files |
| .FIP | Uncommon Files |
| .FIQ | Uncommon Files |
| .FIR | Uncommon Files |
| .FIRE | Uncommon Files |
| .FIRESTORMF | Uncommon Files |
| .FIRMWARE | Uncommon Files |
| .FIRST | Uncommon Files |
| .FIS | Uncommon Files |
| .FISH | Uncommon Files |
| .FISHES | Uncommon Files |
| .FISHTANK | Uncommon Files |
| .FIT | GIS Files |
| .FITS | Raster Image Files |
| .FIU | Uncommon Files |
| .FIV | Uncommon Files |
| .FIVE | Uncommon Files |
| .FIW | Uncommon Files |
| .FIX | Uncommon Files |
| .FIXED | Uncommon Files |
| .FIXER | Uncommon Files |
| .FIXES | Uncommon Files |
| .FIXKERN | Uncommon Files |
| .FIY | Uncommon Files |
| .FIZ | Uncommon Files |
| .FJ0 | Uncommon Files |
| .FJ1 | Uncommon Files |
| .FJ2 | Uncommon Files |
| .FJ3 | Uncommon Files |
| .FJ4 | Uncommon Files |
| .FJ5 | Uncommon Files |
| .FJ6 | Uncommon Files |
| .FJ7 | Uncommon Files |
| .FJ8 | Uncommon Files |
| .FJ9 | Uncommon Files |
| .FJA | Uncommon Files |
| .FJB | Uncommon Files |
| .FJC | Uncommon Files |
| .FJD | Uncommon Files |
| .FJE | Uncommon Files |
| .FJF | Uncommon Files |
| .FJG | Uncommon Files |
| .FJH | Uncommon Files |
| .FJI | Uncommon Files |
| .FJJ | Uncommon Files |
| .FJK | Uncommon Files |
| .FJL | Uncommon Files |
| .FJM | Uncommon Files |
| .FJN | Uncommon Files |
| .FJO | Uncommon Files |
| .FJP | Uncommon Files |
| .FJQ | Uncommon Files |
| .FJR | Uncommon Files |
| .FJS | Uncommon Files |
| .FJSW | Uncommon Files |
| .FJT | Uncommon Files |
| .FJU | Uncommon Files |
| .FJV | Uncommon Files |
| .FJW | Uncommon Files |
| .FJX | Uncommon Files |
| .FJY | Uncommon Files |
| .FJZ | Uncommon Files |
| .FK | Uncommon Files |
| .FK0 | Uncommon Files |
| .FK1 | Uncommon Files |
| Extension | File Description |
| .FK2 | Uncommon Files |
| .FK3 | Uncommon Files |
| .FK4 | Uncommon Files |
| .FK5 | Uncommon Files |
| .FK6 | Uncommon Files |
| .FK7 | Uncommon Files |
| .FK8 | Uncommon Files |
| .FK9 | Uncommon Files |
| .FKA | Uncommon Files |
| .FKB | Uncommon Files |
| .FKC | Uncommon Files |
| .FKD | Uncommon Files |
| .FKE | Uncommon Files |
| .FKF | Uncommon Files |
| .FKG | Uncommon Files |
| .FKH | Uncommon Files |
| .FKI | Uncommon Files |
| .FKJ | Uncommon Files |
| .FKK | Uncommon Files |
| .FKL | Uncommon Files |
| .FKM | Uncommon Files |
| .FKN | Uncommon Files |
| .FKO | Uncommon Files |
| .FKP | Uncommon Files |
| .FKQ | Uncommon Files |
| .FKR | Uncommon Files |
| .FKS | Uncommon Files |
| .FKT | Uncommon Files |
| .FKTMPLT | Uncommon Files |
| .FKU | Uncommon Files |
| .FKV | Uncommon Files |
| .FKW | Uncommon Files |
| .FKX | Uncommon Files |
| .FKY | Executable Files |
| .FKZ | Uncommon Files |
| .FL | Game Files |
| .FL0 | Uncommon Files |
| .FL1 | Uncommon Files |
| .FL2 | Uncommon Files |
| .FL3 | Uncommon Files |
| .FL4 | Uncommon Files |
| .FL5 | Uncommon Files |
| .FL6 | Uncommon Files |
| .FL7 | Uncommon Files |
| .FL8 | Uncommon Files |
| .FL9 | Uncommon Files |
| .FLA | Developer Files |
| .FLAC | Audio Files |
| .FLAG | Uncommon Files |
| .FLAGS | Uncommon Files |
| .FLARE | Uncommon Files |
| .FLASK | Uncommon Files |
| .FLB | Page Layout Files |
| .FLC | Video Files |
| .FLCL | Uncommon Files |
| .FLD | Uncommon Files |
| .FLE | Uncommon Files |
| .FLETCH | Uncommon Files |
| .FLEX | Uncommon Files |
| .FLEXRESP | Uncommon Files |
| .FLF | Misc Files |
| .FLG | Disk Image Files |
| .FLH | Video Files |
| .FLI | Video Files |
| .FLIGS | Uncommon Files |
| .FLINT | Uncommon Files |
| .FLIPCURS | Uncommon Files |
| .FLJ | Uncommon Files |
| .FLK | Data Files |
| .FLKEY | Uncommon Files |
| .FLL | Data Files |
| .FLM | Uncommon Files |
| .FLN | Uncommon Files |
| .FLO | Data Files |
| .FLOBY | Uncommon Files |
