| fel | Fugawi Elevation Library Data |
| fem | Sybase PowerDesigner Free Model |
| fem | Sesam GeniE FEM Data |
| fen | Forsyth–Edwards Notation Data |
| fes | Topicscape Fileless Link Export |
| fet | FET Data |
| ffa | Microsoft Find Fast Status File |
| ffblush | FaceFilter Blush Data |
| ffc | Photometrica Flat Field Correction Data |
| ffdata | Abbyy eFormFiller Data File |
| ffeline | FaceFilter Eye Line Data |
| ffindex | FFmpegSource2 Media Index |
| ffiris | FaceFilter Iris Data |
| ffl | Microsoft Find Fast List |
| ffmakeup | FaceFilter Makeup Data |
| ffo | Microsoft Find Fast Cache |
| ffp | FLAC Fingerprint Data |
| ffp.txt | FLAC Fingerprint Data |
| ffr | Gminos FFR Card |
| ffs | Samsung S5230 Firmware Factory FS File |
| ffshape | FaceFilter Shape Data |
| ffskin | FaceFilter Skin |
| ffs_db | FreeFileSync Database |
| fft | Farm Foresty Toolbox Data |
| ffv | Fisher FirstVue Data |
| ffwp | FormsForWeb Packet |
| ffx | Microsoft Find Fast Index |
| ffxptheme | FlashFXP Toolbar Theme Data |
| fga | Folder Guard Attributes File |
| fgb | Talysurf CCI 3000 Frame Sequence Data |
