| Rank | Abbreviation | Meaning |
|---|
| ***** | IFFA | Interactive Flash Flood Analyzer
| |
| ***** | IFFA | International Fly Fishing Association
| |
| **** | IFFA | International Foundation of Friends of Africa
| |
| **** | IFFA | Iranian Football Fans Association
| |
| *** | IFFA | Internationale Fleischwirtschaftliche Fachmesse
| |
| *** | IFFA | International Frozen Food Association
| |
| *** | IFFA | Independent Federation of Flight Attendants
| |
| *** | IFFA | International Film Festival On Aging
| |
| *** | IFFA | International Freight Forward Association
| |
| *** | IFFA | International Federation of Forwarding Agents
| |
| ** | IFFA | Interchange File Format Amiga
| |
| ** | IFFA | International Federation of Film Archives
| |
| ** | IFFA | Institut Für Forstliche Arbeitswissenschaft
| |
| * | IFFA | Ian Fabulous Freebies Archive
| |
| * | IFFA | International Forum of Funding Agencies
| |
| * | IFFA | International Federation of Football Association
| |
| * | IFFA | International Family Forest Alliance
| |
| * | IFFA | Indigenous Flora and Fauna Association
| |
| * | IFFA | International Firefighters Association
| |
| * | IFFA | infected false femoral aneurysms
| |
| * | IFFA | International Family Forestry Alliance
| |
| * | IFFA | Independent Fine Framers Association
| |