| Abbreviation | Definition |
|---|---|
| ISBC | International Society for the Banning of Chairs |
| ISDN | I See Dollars Now |
| ISDN | I Still Don't No |
| ISDN | Incompatible Silly Digital Nonsense |
| ISDN | Incredibly Speedy Data Now |
| ISDN | It Still Does Nothing |
| ISDP | I See Dead People |
| ISE | Internal Sneezing Error |
| ISEE | Institute of Seriously Expensive Education |
| ISHYGDDT | I Seriously Hope You Guys Don't Do This |
| ISIS | Idiots Stupid, Idiots Stupid |
| ISIS | Insane Senseless Idiotic Shitbags |
| ISIS | Israeli State Intelligence Services |
| ISL | In Sim Life |
| ISN | I Said No |
| ISO | Infringing Software Organization |
| ISO | It's Soon Out |
| ISP | I Sell Promises |
| ISP | Inferior Service Provider |
| ISS | Impotent Sea Snakes |