| knn | Clarion Database Key Data |
| kno | EvREsearch DigIN Serialized Break Model |
| knx | Kronos Workforce Link |
| knxprod | KNX ETS Product Database |
| kob | KASEMAKE Object |
| koc | Koha Offline Circulation Data |
| kof | Reuters Kobra Data |
| kog | EuKaryotic Orthologous Groups Database |
| kok | KaraFun Karaoke Song Data |
| kor | Windows Korean Noise-word List |
| kow | Reuters Kobra Data |
| kp | WinOLS Map Data |
| kpd | Kaspersky Lab Application Description |
| kpn | KPN Tunnel Data |
| kr | Appian Server Data |
| krd | PreFlight Location Database |
| krf | DNSSEC-Tools Keyrec Data |
| krl | OpenSSH Key Revocation Lists Data |
| krx | Siemens NX Reusable Component |
| ksd | IHS Kingdom Seismic Data |
| ksd | KeepSafe Data |
| kse | Keepsake Studio Export File |
| ksg | Kwalitan Segment File |
| ksi | Alloy Blending System KSI Data |
| ksk | Adobe Illustrator Kinsoku Set |
| ksl | Karaoke Song List Creator Data |
| kss | FabTrol MRP KISS File |
| kt3 | KeyText v3 Data |
| ktb | BRLTTY Key Tables Data |
| ktd | Microsoft Dynamics AX Kernel Text Data |
| ktf | KeyTruss Truss Data |
| kti | BRLTTY Subtables Data |
| kti | Kelvin TOP-SET Investigator Data |
| ktl | Knowmia Teach Lesson File |
| ktr | KeyTruss Truss Data |
