| fhr | Family Historian Data |
| fhx | DeltaV Database File |
| fia | FIA Input Data |
| fib | File Investigator Internal Database |
| fid | File Investigator Internal Database |
| fidx | Fiasco Database Index Data |
| fiff | Elekta Neuromag FIFF Data |
| fig | SNES ROM Image FIG |
| fih | File Investigator Internal Database |
| fil | ACL for Windows Data |
| filebolt | Filebolt Encrypted Data |
| fileloc | Mac OS X Finder Internet Location Data |
| filelock | FileLock Data |
| filepart | WinSCP Temporary Data |
| fio | Aldus PhotoStyler Graphics Filter |
| fip | File Investigator Internal Database |
| fis | MATLAB Fuzzy Logic Toolbox FIS File |
| fish | 3D Fish Tank Fish Data |
| fits | HippoDraw FITS Data |
| fiv | File Investigator Internal Database |
| fix | ASL Fixplot Calculated Fixations |
| fjsw | Formulator Tarsia Jigsaw Puzzle |
| fkc | FBackup Catalog File |
| fkd | FotoKiss Photo Set Data |
| fkr | FKR Program Data File |
| fl | DRM Forward Lock |
| fl3 | Adobe Photoshop Flash 3D Document |
| fl7 | PCModWin MODTRAN Output Data |
| flam3 | Fractal Flames |
| flame | Fractal Flames Data |
