| Abbreviation | Definition |
|---|---|
| IETE | Institution of Electronics and Telecommunication Engineers |
| IETS | International Embryo Technology Society |
| IEV | International Entomological Union |
| IEV | Internationaler Entomologischer Verein |
| IFCB | International Federation for Cell Biology |
| IFCC | International Federation of Clinical Chemistry and Laboratory Medicine |
| IFCS | International Federation of Chopin Societies |
| IFCS | International Federation of Classification Societies |
| IFCS | Internet Film Critics Society |
| IFEH | International Federation of Environmental Health |
| IFES | International Field Emission Society |
| IFFS | Fdration Internationale des Socits de Fertilit |
| IFFS | Federacin Internacional de las Sociedades de Fertilidad |
| IFFS | Federación Internacional de las Sociedades de Fertilidad |
| IFFS | Fédération Internationale des Sociétés de Fertilité |
| IFFS | International Federation of Fertility Societies |
| IFGS | International Fantasy Gaming Society |
| IFHGS | International Federation of Human Genetics Societies |
| IFIA | International Federation of Inventors' Associations |
| IFLA | International Federation of Library Associations & Institutions |