| 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 |
| ffcmd | Filter Forge Command Data |
| ffdata | Abbyy eFormFiller Data File |
| ffebrow | FaceFilter Eye Brow Data |
| ffeiris | FaceFilter Eye Iris Data |
| ffelash | FaceFilter Eye Lash Data |
| ffeline | FaceFilter Eye Line Data |
| ffeshadow | FaceFilter Eye Shadow Data |
| ffeye | FaceFilter Eye Data |
| fffilter | FaceFilter Filter Data |
| ffhilight | FaceFilter HiLight Data |
| ffindex | FFmpegSource2 Media Index |
| ffiris | FaceFilter Eye Iris Data |
| ffj | FEMFAT Job Data |
| ffl | Microsoft Find Fast List |
| fflip | FaceFilter Lip Data |
| 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 |
