| Abbreviation | Definition |
|---|---|
| IM | Infinite Mind |
| IMF | Impossible Mission Force |
| INSITE | International Network of Somewhere In Time Enthusiasts |
| IO | Imperial Outpost |
| IOA | Instruments Of Anarchy |
| IOC | Invasion Of Chaos |
| IOD | Instrument Of Destruction |
| IOL | Internal Organ Liquifier |
| IOS | Identified Orbiting Satellite |
| IOTM | Im over the moon |
| IOTM | I'm over the moon |
| IPA | Islesboro Paranormal Activity |
| IPC | Inter Planetary Corps |
| IPKC | Imperial Peace-Keeping Certificate |
| IPR | Infinite Power Reality |
| ISA | International Security Alliance |
| ISA | Interplanetary Strategic Alliance |
| ISC | Imperial Stellar Corps |
| ISD | Imperial Star Destroyer |
| ISE | Inter-Stellar Empire |