| k11 | DataFlex Index |
| k12 | DataFlex Index |
| k2 | DataFlex Index |
| k2p | Kryptel Encrypted Data |
| k3 | DataFlex Index |
| k4 | DataFlex Index |
| k5 | DataFlex Index |
| k6 | DataFlex Index |
| k7 | DCMO6 Emulator Tape Image |
| k7 | DataFlex Index |
| k8 | DataFlex Index |
| k9 | DataFlex Index |
| ka | Karma Assets Data |
| kab | Kmail Addressbook Data |
| kad | NI Kore Data |
| kadf | KetabeAvval Data Format File |
| kal | Hondata KManager Calibration Data |
| kali | Kali Linux Related Data |
| kam | BEL Framework KAM Database |
| kan | Kwalitan Annotation Data |
| kbb | Jetico BestCrypt Key Block Backup |
| kbd | MountFocus Keyboard Designer Keyboard |
| kbf | MyInfo Document |
| kbi | Keirsey Bates Temperament Sorter Index |
| kbk | Medeco XT Codebooks for Keys Data |
| kbp | Keirsey-Bates Temperament Sorter Profile Data |
| kbs | Keyboard Script |
| kbx | GnuPG Keybox File |
| kcc | KeywordConvert Combined List |
| kcd | Kayak Network Definitions Data |
