| 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 |
| ffx | Microsoft Find Fast Index |
| ffxptheme | FlashFXP Toolbar Theme Data |
| fga | Folder Guard Attributes File |
| fgb | Talysurf CCI 3000 Frame Sequence Data |
| fgd | Folder Guard Data File |
| fgdb | Fontographer Mac Database |
| fgf | Nav.Net NG Fusker Generator Data |
| fgp | Folder Guard Password File |
| fgr | FRSGiftRegistry Data File |
| fgt | FreeGantt Skeleton Data |
| fgv | CellexalVR FGV Data |
| fhb | ForeHelp Backup File |
| fhc | Canute FHC Data FIle |
| fhf | Free Hide Folder Backup |
| fhi | ABINIT FHI Data |
| fhq | Family Historian Query |
| fhr | Family Historian Data |
| fht | Family Historian Text Scheme Data |
| fhx | DeltaV Database File |
| fh_proj | Family Historian Project |