| Abbreviation | Definition |
|---|---|
| HWZ | Hermann Weyl Zimmer (German mathematician who helped prove the Peter–Weyl theorem) |
| IA | Irwin Allen |
| IA | Issac Anderson, Judge |
| IACM | India Against Corruption Movement |
| IB | Isaac Butts |
| IDS | Ian Duncan Smith |
| IJ | Indiana Jones |
| IJN | In Jesus Name |
| IKE | Dwight David Eisenhower, United States President |
| IRS | Irwin R. Scheister, wrestler (real name: Lawrence Michael Rotunda) |
| ISD | Ian Stuart Donaldson |
| IWK | Ian W King |
| JA | Jeffrey Atkins |
| JA | Jim Auerbach |
| JA | Jim Austin |
| JA | Joan Andersen |
| JA | John Adams |
| JA | Jonathan Alder |
| JAB | John A. Bilicki |
| JAB | John Alfred Back |