| Extension | 描述 | 檔案格式 |
|---|
| f4v | MP4 Video File | 視頻檔案 |
| fastresume | ReadyNAS Bit Torrent File | Misc Files |
| fb! | FlashGet Partial Download File | Misc Files |
| fb2 | FictionBook 2.0 File | 文字檔 |
| fbl | iGO Map File | Misc Files |
| fcd | First Choice Database File | 資料檔 |
| fcd | Virtual CD Image File | 磁碟映像檔 |
| fdb | Dynamics NAV Database File | 資料檔 |
| fdc | Field Catalog File | 3D Files |
| ff | Call Of Duty Game File | 遊戲檔案 |
| fid | Bruker Aspect NMR Data File | 資料檔 |
| fid | Streamed Video File | 視頻檔案 |
| fig | 3ds Max Figure File | 3D Files |
| fil | Files List File | 資料檔 |
| file | AS/400 Physical File | 系統檔案 |
| fl | Freelancer Saved Game | 遊戲檔案 |
| fla | Adobe Flash Files | Developer Files |
| flac | Free Lossless Audio Codec File | 聲音檔案 |
| flame | Fractal Flame File | 圖檔 |
| flipchart | ActiveInspire Flipchart File | Misc Files |
| flk | File Locker Encrypted File | 加密檔案 |
| flp | Adobe Flash Project File | 多媒體檔案 |
| flt | Aldus Import Filter File | Misc Files |
| flv | Flash Video | 視頻檔案 |
| flvAT | Flash Video | 視頻檔案 |
| fm | FileMaker Pro Spreadsheet File | 試算表檔案 |
| fmp | AutoCAD Font Mapping File | Misc Files |
| fmt | Microsoft Schedule Plus Print File | Misc Files |
| fnt | Font File | 字型檔案 |
| fo | XSL-FO Form File | 資料檔 |
| fol | Windows Mail Folder Settings File | 設定檔 |
| forge | Assassins Creed Audio File | 聲音檔案 |
| fp3 | FileMaker Pro 3 Database File | 資料檔 |
| 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 | 資料檔 |
| frp | FaxRush List File | Misc Files |
| frp | Perform File | Misc Files |
| frw | Rollercoaster Tycoon Game File | 遊戲檔案 |
| fs | F# Source Code File | Developer Files |
| fsb | FMOD Sample Bank File | 聲音檔案 |
| fsh | EA Sports FSH Image File | 圖檔 |
| fx | DirectX Effects File | 系統檔案 |
| fxp | FoxPro Compiled Program File | Developer Files |
| f_i | Prints IPS File | Misc Files |