| fasta | FASTA Sequence |
| fastq | FASTQ Sequence |
| fat | Zinf Theme |
| fau | Creator Collapsed Fault List |
| fav | Microsoft Outlook Navigation Bar |
| favorite | Apple iDVD Favorites Data |
| favs | PlasmaEPG Saved Favorites Data |
| fb! | FlashGet Unfinished File |
| fb1 | FAWAVE Data File |
| fba | FinalBurn Alpha Image |
| fbc | Family Tree Maker Compressed Backup Data |
| fbk | Microsoft Dynamics NAV Database Backup |
| fbk | Family Tree Maker Backup Data |
| fbl | iGO Map file |
| fbn | Sony-Ericsson Phone Flash Filesystem |
| fbr | BrainVoyager QX Fiber Coordinates Data |
| fc1 | FCEUX Saved State |
| fc2 | FCEUX Saved State |
| fc2 | Poser Face Data |
| fc3 | FCEUX Saved State |
| fca | Omnis Web Client Form Cache |
| fcat | Fact200 Categories Data |
| fcc | SiteMinder Forms Credential Collector Data |
| fcdot | ABBYY FlexiCapture Engine Document Definition |
| fch | Gaussian Formatted Checkpoint File |
| fchk | Gaussian Formatted Checkpoint File |
| fci | Erosion 3D Inflow Table |
| fci | Fiery Clone Tool Image |
| fcm | Brother ScanNCut Data |
| fcpcache | Final Cut Pro Cache Data |
| fcpevent | Final Cut Pro Event Data |
| fcs | Canon ZoomBrowser EX Data |
| fcs | Flow Cytometry Standard Data |
| fcst | Delft-FEWS Forecast Data |
| fct | FolderClone Task List |
