| Extension | File Description |
| .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 |
| .FKZ | Uncommon 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 |
| .FLAG | Uncommon Files |
| .FLAGS | Uncommon Files |
| .FLARE | Uncommon Files |
| .FLASK | Uncommon Files |
| .FLCL | Uncommon Files |
| .FLD | Uncommon Files |
| .FLE | Uncommon Files |
| .FLETCH | Uncommon Files |
| .FLEX | Uncommon Files |
| .FLEXRESP | Uncommon Files |
| .FLIGS | Uncommon Files |
| .FLINT | Uncommon Files |
| .FLIPCURS | Uncommon Files |
| .FLJ | Uncommon Files |
| .FLKEY | Uncommon Files |
| .FLM | Uncommon Files |
| .FLN | Uncommon Files |
| .FLOBY | Uncommon Files |
| .FLOOR | Uncommon Files |
| .FLOWER | Uncommon Files |
| .FLOYD | Uncommon Files |
| .FLQ | Uncommon Files |
| .FLU | Uncommon Files |
| .FLUTE | Uncommon Files |
| .FLUX | Uncommon Files |
| .FLW | Uncommon Files |
| .FLY | Uncommon Files |
| .FLYP | Uncommon Files |
| .FLYS | Uncommon Files |
| .FLZ | Uncommon Files |
| .FLZW | Uncommon Files |
| .FM0 | Uncommon Files |
| .FM1 | Uncommon Files |
| .FM2 | Uncommon Files |
| .FM4 | Uncommon 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 |
| .FMF | Uncommon Files |
| .FMG | Uncommon Files |
| .FMGEN | Uncommon Files |
| .FMH | Uncommon Files |
| .FMJ | Uncommon Files |
| .FMK | Uncommon Files |
| .FMM | Uncommon Files |
| .FMMUS | Uncommon Files |
| Extension | File Description |
| .FMN | Uncommon Files |
| .FMO | Uncommon Files |
| .FMORC | Uncommon Files |
| .FMQ | Uncommon Files |
| .FMR | Uncommon Files |
| .FMS | Uncommon Files |
| .FMU | Uncommon Files |
| .FMY | Uncommon 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 |
| .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 |
| .FNU | Uncommon Files |
| .FNV | Uncommon Files |
| .FNW | Uncommon Files |
| .FNX | Uncommon Files |
| .FNY | Uncommon Files |
| .FNZ | Uncommon Files |
| .FN_ | Uncommon 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 |
| .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 |
| .FOLD | Uncommon Files |
| .FOLDER | Uncommon Files |
| .FOLDERS | Uncommon Files |
| .FOM | Uncommon Files |
| .FONT | Uncommon Files |
| .FONT1 | Uncommon Files |
| .FONTASM | Uncommon Files |
| .FONTCHART | Uncommon Files |
| .FONTCOMM | Uncommon Files |
| .FONTGEN | Uncommon Files |
