| icg | Image Comparer Database |
| ichat | iChat Saved Log |
| ici | AMPAC ICI Data |
| icl | ArtIcons Icon Library |
| icl | Mail.dat International Container Label File |
| icm | Image Color Matching Profile |
| icm | Integrated Climatic Model Data |
| icmod | Inner Core Minecraft PE Mod Data |
| icms | RagTime Data |
| icn | OpenFlight Model |
| icns | Mac OS X Icon Resource File |
| iconbox | IconBox Data |
| iconfig | iConfig Data |
| iconset | Mac OS X Icon Resource File |
| icontainer | CandyBar iContainer Data |
| icp | Identity Compass Encrypted Profile |
| icq | ICQ Archive Data |
| icq | QIP Infium ICQ Data |
| icr | Image Comparer Results Data |
| icr | Impromptu Content Report |
| icr | NCSA Telnet Interactive Color Raster Data |
| icsalarm | iCal Alarm Data |
| ict | Cadence ASCII Interconnect Technology File |
| icursorfx | iCursor Effect |
| icx | Windows CE Remote Call Profiler Summary View |
| icxs | iTunes Internal Data |
| id | AOL Instant Messenger Buddy Icon |
| id | Lotus Notes User ID File |
| id2 | Live Messenger Custom Emoticon Metadata |
| id3 | ID3 Metadata |
