| f3s | Faro SCENE 3D Laser Scanner Data |
| f4thor | Thor Filter Data |
| f99 | HEC-RAS Flow File |
| fa | FASTA Sequence |
| facet | Facet Data File |
| fad | LightJockey Fader Data |
| fader | Serato DJ Fader Data |
| faf | Find Any File Data |
| fah | Folding@home Data |
| fai | FASTA Index Data |
| failed | IBM Content Navigator Failed Task Log |
| fak | HP MPE/iX Fixed ASCII KSAM Data |
| fam | PLINK Individual Information File |
| familyfile | Reunion Family |
| fan | Form Z Animation |
| fap | Visage Mpeg-4 ASCII Facial Animation Parameters File |
| 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 |
| faz | DeskMate Generic Character Data |
| fb! | FlashGet Unfinished File |
| fb1 | FAWAVE Data File |
| fba | FinalBurn Alpha Image |
| fbc | Family Tree Maker Compressed Backup Data |
| fbexplore | FileBoss Explorer Data |
| fbk | Family Tree Maker Backup Data |
