| Abbreviation | Definition |
|---|---|
| IFSCS | International Federation of the Societies of Classical Studies |
| IFSM | Fdration Internationale de Mdecine Sportive |
| IFSM | Fédération Internationale de Médecine Sportive |
| IFTM | International Federation of Tropical Medicine |
| IFUW | Fdration internationale des femmes diplmes des universits |
| IFUW | Fédération internationale des femmes diplômées des universités |
| IFUW | International Federation of University Women |
| IGA | International Geothermal Association |
| IGAS | International Grapho Analysis Society |
| IGAS | Irish Group Analytic Society |
| IGBP | Interdisciplinary Society of Biological Psychiatry |
| IGBP | International Geosphere-Biosphere Programme |
| IGD | Grand-Ducal Insitute of Luxemburg |
| IGD | Institut Grand-Ducal de Luxembourg |
| IGES | International Gastrointestinal Electrophysiology Society |
| IGES | International Genetic Epidemiology Society |
| IGF | International Genetics Federation |
| IGHS | Illiana Genealogical and Historical Society |
| IGHS | Illiana Genealogical Historical Society |
| IGHS | Indiana German Heritage Society |