| F | Compressed file archive (FREEZE) |
| F01 | Fax document (Perfect Fax) |
| F06 | Dos screen text font (height= 6 pixels) |
| F07 | Dos screen text font (height= 7 pixels) |
| F08 | Dos screen text font (height= 8 pixels) |
| F09 | Dos screen text font (height= 9 pixels) |
| F10 | Dos screen text font (height= 10 pixels) |
| F11 | Dos screen text font (height= 11 pixels) |
| F12 | Dos screen text font (height= 12 pixels) |
| F13 | Dos screen text font (height= 13 pixels) |
| F14 | Dos screen text font (height= 14 pixels) |
| F15 | Dos screen text font (height= 15 pixels) |
| F16 | Dos screen text font (height= 16 pixels) |
| F2R | Linear music module (Farandole) |
| F3R | Blocked music module (Farandole) |
| F77 | Source code file (FORTRAN 77) |
| F90 | FORTRAN file |
| F96 | Fax document (Frecom FAX96) |
| FAC | Face graphic |
| FAQ | Frequently Asked Questions document |
| FAR | Music module (MOD) (Farandole Composer) |
| FAS | Basic module file (3-D Fassade Plus) |
| FAV | Navigation bar (Microsoft Outlook) |
| FAX | FAX Type image |
| FBK | Backup (Microsoft Dynamics NAV, formerly Navison Financials) |
| FC | Spell Check dictionary file (Harvard Graphics) |
| FCD | Virtual CD-ROM file |
| FCM | Binary file patch (Forward Compression) |
| FD | Field offsets for compiler (DataFlex) |
| FDB | Database (Navison Financials) |
| FDB | Firebird database file |
| FDW | Document form (F3 Design and Mapping) |
| FEB | Button Bar for Figure Editor (WordPerfect for Windows) |
| FEM | CADRE Finite Element Mesh |
| FES | Topicscape file for fileless exports to Windows |
| FF | Outline Font description (AGFA CompuGraphics) |
| FFA | MS find fast file |
| FFF | GUS PnP bank file |
| FFL | Image file (PrintMaster Gold) |
| FFO | MS fast find file |
| FFT | Final Form Text (part of IBM's DCA) |
| FFX | MS fast find file |
| FH3 | Aldus Freehand 3 drawing (Vector graphic) |
| FH4 | Aldus Freehand 4 drawing (Vector graphic) |
| FH9 | Macromedia Freehand 9 graphic file |
| FI | File Interface (FORTRAN) |
| FIF | Fractal Image |
| FIG | REND386/AVRIL file |
| FIL | File List Object (dBase Application Generator) |
| FILE | AS/400 physical file |
| FIN | Print formatted text (Perfect Writer) |
| FIT | File index table (Microsoft Windows NT) |
| FITS | Flexible Image Transport System file |
| FIX | Patch file (Generic) |
| FKY | Macro (Microsoft FoxPro) |
| FLA | Movie (Macromedia Flash) |
| FLAC | Free Lossless Audio Compression file |
| FLB | Format library (Papyrus) |
| FLC | FLIC animation (AutoDesk) |
| FLD | Field define module file (3-D Fassade Plus) |
| FLF | License (Navison Financials) |
| FLF | Delived form (Corel Paradox) |
| FLI | Font library (EmTeX) |
| FLM | Film Roll (AutoCAD) |
| FLO | FlowCharter file (MicroGrafx) |
| FLP | Family Lawyer Saved Document |
| FLS | Filelist document (Farrukh Imposition Publisher) |
| FLS | ArcView GIS help file |
| FLT | Filter (Corel) |
| FLV | Macromedia Flash Video file |
| FLW | Kivio flowchart file |
| FLX | Compiled binary file (DataFlex) |
| FM | FrameMaker Document (Adobe) |
| FM | Spreadsheet (FileMaker Pro) |
| FM1 | Spreadsheet (Lotus 1-2-3, version 2.x) |
| FM3 | Spreadsheet (Lotus 1-2-3, version 3.x) |
| FMB | File Manager button bar (WordPerfect for Windows) |
| FMF | Font or Icon (IBM LinkWay) |
| FMK | MakeFile (FORTRAN PowerStation) |
| FML | Mirror list (Oracle) |
| FMO | Compiled format (dBase IV) |
| FMP | Database file (FileMaker Pro) |
| FMT | Print file (Microsoft Schedule+) |
| FMX | Executable form, (Oracle,v4.x and later) |
| FN3 | Font (Harvard Graphics) |
| FNC | Fixed neighbors constraint file in RMC++ application |
| FND | Saved Search (Find applet) (Microsoft Explorer) |
| FNG | Font group (Font Navigator) |
| FNK | Module (FunkTracker) |
| FNT | Font (Microsoft Windows) |
| FNX | Inactive font (Exact) |
| FO1 | Font (Borland Turbo C) |
| FO2 | Font (Borland Turbo C) |
| FOG | Fontographer font |
| FOL | Saved message folder (1st Reader) |
| FOLDER | Windows Explorer folder file |
| FON | Call log (Procomm Plus) |
| FOR | Form (WindowBase) |
| FOT | Installed TrueType font (Microsoft Windows Font Installer) |
| FP | FileMaker Pro file |
| FP1 | "Flying Pigs" screensaver datafile (Microsoft Windows 9.x) |
| FP3 | FileMaker Pro v.3 & 4 document file |
| FP5 | Document file (FileMaker Pro v.5) |
| FPC | Catalog file (FoxPro) |
| FPT | Memo fields (Microsoft FoxPro) |
| FPW | Floorplan drawing (FloorPlan Plus for Windows) |
| FPX | Bitmap (FlashPix) |
| FR3 | Renamed dBaseIII+ form (dBase IV) |
| FRF | Font (FontMonger) |
| FRG | Uncompiled report (dBase IV) |
| FRK | Zip (compressed ) file (Macintosh) |
| FRM | Document (FrameMaker or FrameBuilder) |
| FRO | Compiled report (dBase IV) |
| FRP | Form (PerForm PRO Plus) |
| FRS | Screen Font Resource (WordPerfect for Windows) |
| FRT | Report menu (FoxPro) |
| FRX | Report (Microsoft FoxPro) |
| FSF | fPrint Audit Tool |
| FSL | Form (Paradox for Windows) |
| FSM | Sample file (Farandoyle) |
| FST | Linkable program (dBFast) |
| FSX | Data (Lotus 1-2-3) |
| FT | Full text index (Lotus Notes) |
| FTB | Index file (Roots3) |
| FTF | Client access data specification file (AS/400) (Client to Server) |
| FTG | Help system full-text search group file (Microsoft Windows) |
| FTM | Font (MicroGrafx) |
| FTP | File transfer protocol (Internet Generic) |
| FTS | Help system full-text search index (Windows) |
| FTW | Document file (Family Tree Maker) |
| FW | Database (Framework II) |
| FW2 | Database (Framework II) |
| FW3 | Database (Framework III) |
| FW4 | Database (Framework IV) |
| FWB | Data file backup for file splitting configuration (FileWrangler) |
| FWP | Microsoft FrontPage Web package (archive format for Web site content) |
| FWS | Data file for file splitting configuration (FileWrangler) |
| FX | On-Line guide (FastLynx) |
| FXD | Phonebook (FAXit) |
| FXP | Compiled source code (FoxPro) |
| FXS | Fax Transmit graphic (WinFax) |
| FZB | Bank dump file (Casio FZ-1) |
| FZF | Full dump file (Casio FZ-1) |
| FZV | Voice dump file (Casio FZ-1) |
| HIV | Windows NT Registry Hive |
