| hub | Lattice Reveal Analyzer HUB Data |
| hud | HUD Maker File |
| SmartWare HUD Dictionary Data |
| huf | DtSearch Huffman Compression Table |
| hug | Warrior Tool Heading Data |
| huh | HydroCAD Unit Hydrograph Definitions |
| hun | Personal Paint Hungarian Language Data |
| hut | WaterGEMS Transient Analysis Output Log |
| hv | Microsoft Windows Mobile Hive |
| hvc | HotDocs Variable Collection File |
| hvd | HoverDesk Theme |
| Yamaha HV Voice Dictionary Data |
| hve | Microsoft Windows 8 AMCache Registry Hive |
| hvi | M3601A HVI Data |
| hvif | Haiku Vector Icon Format Data |
| hvs | Yamaha HV-Script |
| hvx | Lightwave 3D Hypervoxel Data |
| hvz | HoloViews Exported Data |
| hyperVIEW Simulation Data |
| hw | Marvelous Designer Hardware ID Data |
| hwas | eXtendable Wad Editor HWAS Data |
| hwdb | Linux Hardware Database |
| hwe | PLINK Hardy-Weinberg Exact Test Statistic Report |
| hwf | Hantek HDG2000B Wave Format Data |
| hwl | BrailleNote Apex License Key File |
| HttpWatch Watch Log |
| hwof | Microsoft Office for Mac Help Data |
| hwpml | Hangul Word Processor Markup Language Data |
| hwrx | Microvellum Hardware File |
| hwt | Huawei Phone Theme |
| hwv | Hades Waveform Viewer Data |
| hwx | RSNetWorx Registration Data |
| hx | Amira 3D Mesh Data |
| hx1 | Microsoft Windows HX1 Data |
| hxb | QCTest Data |
| hxconv | Huelix Audio Converter Session Information |
| hxd | Microsoft Help 2 Validator Data |
| hxg | Microsoft Help 2 Filter Cache |
| hxh | Microsoft Help 2 Merged TOC |
| hxi | Microsoft Help 2 Compiled Help Index |
| hxp | HyperX NGENUITY Presets Data |
| hxq | Microsoft Help 2 Query Data |
| hxr | Microsoft Help 2 Combined Attribute Index |
| hxw | Microsoft Help 2 Merged Index |
| hy1 | Corel Ventura Publisher Hyphenation Algorithm Data |
| hy2 | Corel Ventura Publisher Hyphenation Algorithm Data |
| hy3 | Hy-Tek Meet Manager Results Data |
| Hy-Tek Team Manager Data |
| hyb | HYB Hybrid Data |
| hyc | Corel WordPerfect Internal Data |
| hyd | ANSYS AQWA ASCII Hydrodynamic Database |
| CARE-S InfoWorks Hydrograph Data |
| Corel WordPerfect Hyphenation Dictionary |
| MARIN Hydrodynamic Database File |
| WRAP Single Hydrology Data |
| hym | Hymarc Hyscan 3D Scan Data |
| hyn | HydroNet Explorer Component Information |
| hyp | HyperLynx BoardSim PCB Layout |
| SmartWare HYP Dictionary Data |
| hyper | Tableau Extract Data |
| hypesymbol | Hype Symbol Cache Data |
| hyq | CARE-S Depth Hydrographs for Gauged Pipes |
| hys | Globe HySales Client Data |
| hyv | CARE-S InfoWorks Velocity Hydrograph Data |
| Team Manager 1 Meet Setup File |
| hzd | SeisWorks Horizon Datafile |
| hzf | Home Inspector Pro Inspection Data |
| Neosat Fixes |
| hzn | Observer Pro Horizon Data |
| hzs | CrossWorks for ARM Session Data |
| i1c | IBM Voice Type Languages Newuser Data |
| i1i | IBM Voice Type Languages Newuser Data |
| i2b | Invoice2go Product Data |
| i2c | IBM Voice Type Languages Newuser Data |
| i2g | Intergeo I2G Geometric File |
| i2s | Green Kenue 2D Lineset Data |
| i32 | LabVIEW I32 Data |
| i3dm | Cesium Instanced 3D Tiles Data |
| i3ml | I3ML Data |
| i3s | Green Kenue 3D Lineset Data |
