| Abbreviation | Definition |
|---|---|
| IRS | Intimate Relations Schedule |
| IRS | It's Really Sexy |
| IRT | I'll Remember That |
| IRT | In Regard To |
| IRYO | I Respect Your Opinion |
| IS | It's Simple |
| ISA | It's So Annoying |
| ISAF | I Swallowed A Fly |
| ISB | I Should Be .... |
| ISBK | I'm So Brooklynese |
| ISC | Internet Slang Chat |
| ISDC | I Seriously Don't Care |
| ISDK | I Still Don't Know |
| ISE | Internet Shakespeare Editions |
| ISF | In So Far |
| ISH | I Say Hi |
| ISH | International S*** Hub |
| ISHYGDDT | I Seriously Hope You Guys Don't Do This |
| ISILWY | I'm Still In Love With You |
| ISIS | I Slaughter all I See |