| ksd | IHS Kingdom Seismic Data |
| KeepSafe Data |
| ksds | VSE/VSAM Key Field Sequence Data |
| kse | Keepsake Studio Export File |
| kseqs | SAM Kestrel Sequence Database |
| ksf | KMESS Source Data |
| KMPlayer Skin Data |
| 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 |
| K-ForCE Score Sheet |
| kt3 | KeyText v3 Data |
| ktb | BRLTTY Key Tables Data |
| ktd | Microsoft Dynamics AX Kernel Text Data |
| ktf | KeyTruss Truss Data |
| kti | BRLTTY Subtables Data |
| Kelvin TOP-SET Investigator Data |
| ktl | Knowmia Teach Lesson File |
| LILO Boot Loader Data |
| ktr | Kettle Transformation Data |
| KeyTruss Truss Data |
| ktspack | KeyTruss Truss Archive Data |
| ktt | KeyText Data |
| ktx | KiTTY Data |
| Kwalitan Text |
| ku | my Knowledge Explorer Knowledge Unit |
| kud | Kaspersky Lab Unicode Application Description |
| kun | K-Board Data |
| kup | Karaoke Song List Creator Database |
| kv3 | KM-NET Viewer v4 Workspace |
| kv6 | Ken Voxlap 6 Model |
| kvb | Klick-N-View Business Cards Data |
| kvc | Knit Visualizer 2.0 Chart |
| kvk | Keyman Desktop Virtual Keyboard File |
| kvl | Knit Visualizer Library |
| kvml | KWordQuiz Data |
| kvp | Key-Value Pair Data |
| kvt | KVIrc Theme Data |
| kvw | Google Earth Workspace Data |
| kvx | KM-NET Viewer v5 Workspace |
| Voxel Data |
| kwa | KWIVER Video Data |
| kwb | BrailleNote KeyWord Braille |
| Kwalitan Work File |
| kwc | Flipnote Studio 3D Comments Data |
| kwd | Klusta Kwik RAW Data |
| kwe | kCura Win Edds Data |
| kwf | Kwalitan Word List |
| kwi | KIWI Navigation Data |
| kwik | Klusta Kwik Data |
| kwl | KWalletManager Data |
| kwm | WebMoney Key |
| kwo | KeyWallet Encrypted Password Storage |
| kws | Alexa Voice Service Keyword Spotting Data |
| KeyWallet Skin |
| kwt | BrailleNote KeyWord Text |
| kwu | KWUROHR Data |
| kwx | kCura Win Edds Export Data |
| Klusta Kwik Spiking Data |
| kwy | Keepaway Framework Learning Curve Data |
| kwz | Flipnote Studio 3D Flipnote Data |
| kxp | Key Home Gourmet Data File |
| kxs | kX Project Skin |
| kxw | Pedigree Central Database Index |
| kxy | SUPCRT92 K Values File |
| ky | PeachText List Manager KY Data |
| kyn | ALSee Thumbnail Cache |
| kyr | Lotus Domino Server Keyring |
| kzm | Karizma Designer Album |
| kzx | Kerkythea Zipped XML Material Data |
| l | FractInt L-System Fractal Data |
| l01 | EnCase Logical Evidence Data |
| l16 | JRiver Media Center L16 Data |
| l1b | RFSCAT Simulator Pseudo Level 1b Data |
| l2g | SATURN Suite Link to Group Data |
| l2l | IBM Voice Type Languages Addword Data |
| l2p | IBM Voice Type Languages Addword Data |
| l32 | Swift Create Caption Data |
