| Abbreviation | Definition |
|---|---|
| JL | Justice League |
| JLA | Justice League of America |
| JLA | Justice Legion Alpha |
| JLS | Javelin Light Spear |
| JLU | Justice League Unlimited |
| JM | Jedi Masters |
| JOB | Jedi Old Boys |
| JOR | Jedi Of The Republic |
| JPIC | Justice, Peace, and Integrity of Creation |
| JSW | Jupiter Star Warrior |
| JT | Jedi Trainer |
| K | Kookazoid |
| KAAF | Klingon Academy Assault Force |
| KAI | Klingon Armada International |
| KAREN | Kinetic Android Responsible For Exploration And Nullification |
| KBD | King Black Dragon |
| KBF | Klingon Black Fleet |
| KD | King of Dragons |
| KDC | Klingon Imperial Diplomatic Corps |
| KDFN | Klingon Defense Force Imperial Navy |