| kfs | Pegasus Mail Static Kill Data |
| kft | Matrox X.Tools Keyframe Data |
| kfx | Kofax Capabilities File |
| kgf | UniCERT Key Generation Data |
| kgm | KeyTERRA-FIRMA Ground Model Data |
| kgs | Kogeo Session Data |
| kgtemp | KuGou Temporary Cache Data |
| kh | Khmer-Protocols Hash Table |
| khd | Microsoft Dynamics AX Kernel Help Documentation |
| khe | kHED 3D Model Data |
| khf | Kwalitan Tree Structure |
| khs | Kwalitan History Data |
| khtmp | Google Earth Temporary Location Data |
| khub | Offline Course Player Data |
| kids | SAM Kestrel Sequence Id Data |
| kif | Autodesk AutoCAD Key Index File Format Data |
| kim | Commodore KIM-1 Image |
| kin | Kinemage Protein Structure Image |
| kine | KineMaster Data |
| kip | OA-KIP Client Data Transfer File |
| kipf | Kemper Profiler Presets Data |
| kipr | Kemper Profiler Profile Data |
| kipx | QQ Messenger Theme Data |
| kir | Kiruna Magnetometer Data |
| kismac | KisMAC Webservice |
| kiwi | KiwiViewer Scene |
| kjb | Kettle Job File |
| kjv | theWord King James Version Module |
| kk0 | KFK File Splitter Splitted Data |
| kk1 | ViewChoice KK1 Data |
| kk2 | ViewChoice KK2 Data |
| kkk | Filmetrics F20 Material Data |
| kkw | Adobe RoboHelp Keyword Help Project Index |
| kla | KLARFF Map Data |
| klb | KidPix Stamp Album |
