| ftw | FontTwister Saved Text Effect |
| ftz | fastText Quantized Model |
| fuc | Frequently Used Commands |
| fud | FairUse Wizard Data File |
| ful | Microsoft Backup File List |
| fun_list | Free Uninstaller Data |
| furl | Fact200 Main Index Data |
| fus | FXpansion Uninstall Script |
| futr | NetIQ Identity Manager Future-dated Infotype Cache |
| fv | Fresh View Thumbnail Cache |
| fvb | TAC Vista Database Backup |
| fvd | DatABEL Filevector Data |
| fve | BitLocker Full Volume Encryption File |
| fvf | FlukeView File |
| fvi | DatABEL Filevector Index |
| fvl | Sanscript Library Cabinet File |
| fvp | ANSYS Fluent Path Line Data |
| fvr | NoteTab Favorites File |
| fvs | Forest Vegetation Simulator Tree Data |
| fvu | File Validation Utility Report |
| fw2 | Framework II File |
| fwaction | Freeway Action |
| fwactionb | Freeway Action Bundle |
| fwbackup | Freeway Backup |
| fwc | FWS Sonde Import Data |
| fwd | Bentley InRoads Survey Field Book |
| fwdict | Freeway Pro User Dictionary |
| fwe | FWS Field Data |
| fwf | Bentley InRoads Survey Feature Table Data |
| fwiz | Autodesk Inventor Stress Analysis FWIZ Data |
| fwl | Firewall Builder Library |
| fwn | FreeWave Network Data |
| fwr | Faceware Analyzer Tracking Data |
| fxb | Cubase FX Bank |
| fxf | IBM Endpoint Manager Action |