| knf | Orchida Knitting System Data |
| knj | CDE Japanese Kanji Data |
| knm | iWork Keynote Macro |
| knn | Clarion Database Key Data |
| knnk | OmniPage Internal Data |
| kno | EvREsearch DigIN Serialized Break Model |
| knx | Kronos Workforce Link |
| knxprod | KNX ETS Product Database |
| knxtempl | KNX ETS Device Template |
| kob | KASEMAKE Object |
| koc | Koha Offline Circulation Data |
| kof | Reuters Kobra Data |
| kog | EuKaryotic Orthologous Groups Database |
| kok | KaraFun Karaoke Song Data |
| kon | Yahoo! Widgets XML Data |
| kor | Windows Korean Noise-word List |
| kow | Reuters Kobra Data |
| kp | WinOLS Map Data |
| kpa | Korg KAOSS Pad KP3 Data |
| kpd | Kaspersky Lab Application Description |
| kpe | NI KORE Performance Data |
| kpn | KPN Tunnel Data |
| kqba | KeyQuencer Data |
| kr | Appian Server Data |
| krd | PreFlight Location Database |
| krf | DNSSEC-Tools Keyrec Data |
| krg | Sybase Adaptive Server Information Data |
| krg | Kraken Rigging Framework Data |
| krl | OpenSSH Key Revocation Lists Data |
| krm | Kenwood CD Player Firmware |
| krn | Humdrum Toolkit KERN Data |
| krx | Siemens NX Reusable Component |
| ks-ia1 | Infinite Algebra 1 Data |
| ks-ia2 | Infinite Algebra 2 Data |
| ksd | IHS Kingdom Seismic Data |