| Extension | File Description |
| .FLOOR | Uncommon Files |
| .FLOW | Data Files |
| .FLOWER | Uncommon Files |
| .FLOYD | Uncommon Files |
| .FLP | Disk Image Files |
| .FLQ | Uncommon Files |
| .FLR | Text Files |
| .FLS | GIS Files |
| .FLT | Data Files |
| .FLU | Uncommon Files |
| .FLUTE | Uncommon Files |
| .FLUX | Uncommon Files |
| .FLV | Video Files |
| .FLW | Uncommon Files |
| .FLX | CAD Files |
| .FLY | Uncommon Files |
| .FLYP | Uncommon Files |
| .FLYS | Uncommon Files |
| .FLZ | Uncommon Files |
| .FLZW | Uncommon Files |
| .FM | Spreadsheet Files |
| .FM0 | Uncommon Files |
| .FM1 | Uncommon Files |
| .FM2 | Uncommon Files |
| .FM3 | Settings Files |
| .FM4 | Uncommon Files |
| .FM5 | Database Files |
| .FM6 | Uncommon Files |
| .FM7 | Uncommon Files |
| .FM8 | Uncommon Files |
| .FM9 | Uncommon Files |
| .FMA | Uncommon Files |
| .FMB | Uncommon Files |
| .FMC | Uncommon Files |
| .FMD | Uncommon Files |
| .FMDTOOL | Uncommon Files |
| .FME | GIS Files |
| .FMF | Uncommon Files |
| .FMG | Uncommon Files |
| .FMGEN | Uncommon Files |
| .FMH | Uncommon Files |
| .FMI | GIS Files |
| .FMJ | Uncommon Files |
| .FMK | Uncommon Files |
| .FML | Game Files |
| .FMM | Uncommon Files |
| .FMMUS | Uncommon Files |
| .FMN | Uncommon Files |
| .FMO | Uncommon Files |
| .FMORC | Uncommon Files |
| .FMP | Web Files |
| .FMQ | Uncommon Files |
| .FMR | Uncommon Files |
| .FMS | Uncommon Files |
| .FMT | Settings Files |
| .FMU | Uncommon Files |
| .FMV | GIS Files |
| .FMW | GIS Files |
| .FMX | Plugin Files |
| .FMY | Uncommon Files |
| .FMZ | CAD Files |
| .FMZIP | Uncommon Files |
| .FN0 | Uncommon Files |
| .FN1 | Uncommon Files |
| .FN2 | Uncommon Files |
| .FN3 | Uncommon Files |
| .FN4 | Uncommon Files |
| .FN5 | Uncommon Files |
| .FN6 | Uncommon Files |
| .FN7 | Uncommon Files |
| .FN8 | Uncommon Files |
| .FN9 | Uncommon Files |
| .FNA | Uncommon Files |
| .FNB | Uncommon Files |
| .FNC | CAD Files |
| Extension | File Description |
| .FND | Misc Files |
| .FNE | Uncommon Files |
| .FNF | Uncommon Files |
| .FNG | Uncommon Files |
| .FNH | Uncommon Files |
| .FNI | Uncommon Files |
| .FNJ | Uncommon Files |
| .FNK | Uncommon Files |
| .FNL | Uncommon Files |
| .FNM | Uncommon Files |
| .FNN | Uncommon Files |
| .FNO | Uncommon Files |
| .FNP | Uncommon Files |
| .FNQ | Uncommon Files |
| .FNR | Uncommon Files |
| .FNS | Uncommon Files |
| .FNT | Font Files |
| .FNU | Uncommon Files |
| .FNV | Uncommon Files |
| .FNW | Uncommon Files |
| .FNX | Uncommon Files |
| .FNY | Uncommon Files |
| .FNZ | Uncommon Files |
| .FN_ | Uncommon Files |
| .FO | Data Files |
| .FO$ | Uncommon Files |
| .FO0 | Uncommon Files |
| .FO1 | Uncommon Files |
| .FO2 | Uncommon Files |
| .FO3 | Uncommon Files |
| .FO4 | Uncommon Files |
| .FO5 | Uncommon Files |
| .FO6 | Uncommon Files |
| .FO7 | Uncommon Files |
| .FO8 | Uncommon Files |
| .FO9 | Uncommon Files |
| .FOA | Uncommon Files |
| .FOB | Data Files |
| .FOC | Uncommon Files |
| .FOCF | Uncommon Files |
| .FOD | Uncommon Files |
| .FOE | Uncommon Files |
| .FOF | Uncommon Files |
| .FOG | Uncommon Files |
| .FOH | Uncommon Files |
| .FOI | Uncommon Files |
| .FOJ | Uncommon Files |
| .FOK | Uncommon Files |
| .FOL | Database Files |
| .FOLD | Uncommon Files |
| .FOLDER | Uncommon Files |
| .FOLDERS | Uncommon Files |
| .FOM | Uncommon Files |
| .FON | Font Files |
| .FONT | Uncommon Files |
| .FONT1 | Uncommon Files |
| .FONTASM | Uncommon Files |
| .FONTCHART | Uncommon Files |
| .FONTCOMM | Uncommon Files |
| .FONTGEN | Uncommon Files |
| .FONTREPORT | Uncommon Files |
| .FONTRIX | Uncommon Files |
| .FONTS | Uncommon Files |
| .FONTYX1 | Uncommon Files |
| .FONTYX2 | Uncommon Files |
| .FOO | Uncommon Files |
| .FOODS | Uncommon Files |
| .FOOTER | Uncommon Files |
| .FOP | Data Files |
| .FOQ | Uncommon Files |
| .FOR | Developer Files |
| .FORCE | Uncommon Files |
| .FORECAST | Uncommon Files |
| .FORGE | Game Files |
| .FORM | Uncommon Files |
