| fds | JetForm FormFlow Data |
| fdsrch2 | FeedDemon Search Data |
| fdt | Lucene Field Data |
| fdt | Visilogic Utilities Full Data Table |
| fdx | Food Data Exchange File |
| fdx | Lucene Field Index |
| fdxsl2 | FeedDemon Newspaper Style |
| fdxsl4 | FeedDemon Newspaper Style |
| fe | Surface Evolver Data File |
| feap | Enterprise Architect Repository |
| feat | Feature Chemical Modeller Output Data |
| feb | Corel WordPerfect FE Buttons Data |
| feb | Sybase PowerDesigner Free Model Backup |
| fedb | ANSYS Workbench FE Modeler Data |
| fee | Precision Fees Data |
| feed | JRiver Media Center Feed Data |
| feed-ms | Microsoft RSS Feed Store |
| feedback | Microsoft Expression SketchFlow Feedback Data |
| fef | Steuer 2001 FEF Data |
| fek | Altair FEKO Input Data |
| fel | Fugawi Elevation Library Data |
| fem | Algor Simulation FEA Model |
| fem | Sesam GeniE FEM Data |
| fem | Sybase PowerDesigner Free Model |
| fen | Forsyth–Edwards Notation Data |
| ferp | Extensions Manager Preferences Data |
| fes | Topicscape Fileless Link Export |
| fet | FET Data |
| fetchmirror | Fetch Mirroring Data |
| fev | FLAMES Environment Variables Data |
| fext | Extensions Manager Preferences Data |
| fe_launch | FCS Express Launch Data |
| ff2 | FlashFiler 2 Database |
| ff2 | Softrans Hello Engines! FF2 Data |
| ffa | Microsoft Find Fast Status File |
