| IDL | 1. Inštitút medzinárodného práva (Institute of International Law) 2. international date line |
|---|---|
| IIL | Institute of International Law (skr.) |
| IIP | International Institute of Philosophy (skr.) |
| IPI | International Press Institute (skr.) |
| ISI | International Statistical Institute |
| ITI | International Theatre Institute (skr.) |
| NSI | National Security Institute (skr.) |