| Extension | Description | File Type |
|---|
| f4v | MP4 Video File | Video Files |
| fastresume | ReadyNAS Bit Torrent File | Misc Files |
| fb! | FlashGet Partial Download File | Misc Files |
| fb2 | FictionBook 2.0 File | Text Files |
| fbl | iGO Map File | Misc Files |
| fcd | First Choice Database File | Data Files |
| fcd | Virtual CD Image File | Disk Image Files |
| fdb | Dynamics NAV Database File | Data Files |
| fdc | Field Catalog File | 3D Files |
| ff | Call Of Duty Game File | Game Files |
| fid | Bruker Aspect NMR Data File | Data Files |
| fid | Streamed Video File | Video Files |
| fig | 3ds Max Figure File | 3D Files |
| fil | Files List File | Data Files |
| file | AS/400 Physical File | System Files |
| fl | Freelancer Saved Game | Game Files |
| fla | Adobe Flash Files | Developer Files |
| flac | Free Lossless Audio Codec File | Audio Files |
| flame | Fractal Flame File | Graphic Files |
| flipchart | ActiveInspire Flipchart File | Misc Files |
| flk | File Locker Encrypted File | Encrypted Files |
| flp | Adobe Flash Project File | Multimedia Files |
| flt | Aldus Import Filter File | Misc Files |
| flv | Flash Video | Video Files |
| flvAT | Flash Video | Video Files |
| fm | FileMaker Pro Spreadsheet File | Spreadsheet Files |
| fmp | AutoCAD Font Mapping File | Misc Files |
| fmt | Microsoft Schedule Plus Print File | Misc Files |
| fnt | Font File | Fonts Files |
| fo | XSL-FO Form File | Data Files |
| fol | Windows Mail Folder Settings File | Settings Files |
| forge | Assassins Creed Audio File | Audio Files |
| fp3 | FileMaker Pro 3 Database File | Data Files |
| fp3 | Floor Plan 3D Drawing File | 3D Files |
| fpt | FoxPro Memo Field File | Developer Files |
| frf | FontMonger Database File | Misc Files |
| frm | MySQL Database Format File | Data Files |
| frp | FaxRush List File | Misc Files |
| frp | Perform File | Misc Files |
| frw | Rollercoaster Tycoon Game File | Game Files |
| fs | F# Source Code File | Developer Files |
| fsb | FMOD Sample Bank File | Audio Files |
| fsh | EA Sports FSH Image File | Graphic Files |
| fx | DirectX Effects File | System Files |
| fxp | FoxPro Compiled Program File | Developer Files |
| f_i | Prints IPS File | Misc Files |