| fsi | FME Feature Store Spatial Index Data |
| fsif | MyLabel Designer Deluxe Data |
| fsk | Atari 8-bit Tape Data |
| fsl | Corel Paradox Compiled Form |
| fsm | Splitty Master Split Data |
| fso | Adobe Flash Media Server Remote Shared Object |
| fsp | FormScape Branch Data |
| fsp | iGO Primo Map File |
| fsqueue | FeedStation Queue Data |
| fsrc | Fact200 Source Code |
| fss | Micrografx Picture Publisher Registration Data |
| fss | PaperPort Slideshow Data |
| fss | Splitty Data Split |
| fssx | FolderSizes Snapshot Data |
| fst | FAST Input Data |
| fst | FastStats Analyzer Data |
| fst | FL Studio State Data |
| fst | GAUSS Engine String Data |
| fst | PLINK Fixation Index Report |
| fst | ZOOM MRS-802 FAST Data |
| fstat | SAM Fragfinder Scoring Data |
| fsthumb | Wondershare Filmora Thumbnail Cache |
| fstrm | Frame Streams Protocol Data |
| fsw | Random FlashBackup Flash Data |
| fsx | FormSaver Fields Data |
| fsx | Lotus 1-2-3 FSX Data |
| fsxml | FreeSWITCH XML Data |
| fsz | Fractal Zplot Data |
| ft | EdgeCAM Feature Template |
| ft | Lotus Notes Full-text Index |
| fta | OpenFTA File |
| ftbl | PIPE-FLO Fluid Data Table |
| ftch | Extensis Portfolio Image Database |
| ftes | Autodesk Inventor Stress Analysis Test Data |
| ftf | Xperia X10 Phone FTF Firmware |
