| hof | OMSI HOF Data |
| hog | Descent Mission File |
| honmod | HoN Modification Manager File |
| hop | The Incredibles Data File |
| hop | Spongebob Squarepants: The Movie Data |
| hot | The Sims Sound |
| hotspot | Homeworld Cursor Information Data |
| hpi | Spring HAPI Compressed Data File |
| hpk | Tropico 3 Game Data |
| hps | HPL2 Script |
| hqm | Minecraft Hardcore Questing Mode Data |
| hqr | Little Big Adventure Scene Data File |
| hsd | Highway Pursuit Game Data |
| hsv | Diablo: Hellfire Single Player Character Data |
| htg | HackTheGame Mission Pack |
| hul | Re-Volt Collision Data |
| hum | OMSI Human Configuration File |
| hva | Command and Conquer:Tiberian Sun Game Data |
| hvd | Highway Pursuit Game Data |
| hvp | Obscure Game Data |
| hwd | Hedgewars Demo |
| hwmap | Hedgewars Drawn Map |
| hws | Hedgewars Saved Game |
| hxm | Descent 2 Resource Modification |
| i3chr | Point Blank Game Data |
| i3pack | Point Blank Game Data |
| i3s | Point Blank Game Data |
| iao | ImperiumAO Game Data |
| ib2 | IncrediBots 2 Saved Challenge |
| ib3 | IncrediBots 3 Saved Challenge |
| ibre | IncrediBots Saved Replay |
| ibro | IncrediBots Robot |
| ibt | Texture and Model Data |
| idm | Indigo Prophecy Game Archive |
| idx0 | Runescape Cache Index |
