| ISDN | I See Dollars Now
| Others |
| ISDN | I Still Don't Need
| Others |
| ISDN | I Still Don't No
| Others |
| ISDN | Inas Schule der Doppelten Negation
| Others |
| ISDN | Incompatible Silly Digital Nonsense
| Others |
| ISDN | Incredibly Speedy Data Now
| Others |
| ISDN | Independent School Diversity network
| Others |
| ISDN | Indian Standard Digital Network
| Others |
| ISDN | Integrated Services Data Network
| Others |
| ISDN | Integrated Services Digital Network
| Others |
| ISDN | Integrated Services for Digital Network
| Others |
| ISDN | Integrated System Development Network
| Others |
| ISDN | Interdisciplinary Symposium on Decision Neuroscience
| Others |
| ISDN | International Society for Developmental Neuroscience
| Others |
| ISDN | Is A Switched Digital Network
| Others |
| ISDN | Isosorbide dinitrate
| Others |
| ISDN | It Still Does Nothing
| Others |