| Rank | Abbreviation | Meaning |
|---|
| ***** | IFNA | Islamic Foundation of North America
| |
| ***** | IFNA | Interferon Alpha Gene
| |
| ***** | IFNA | interferon-alpha
| |
| **** | IFNA | Islamic Forum of North America
| |
| **** | IFNA | International Forum of News Agencies
| |
| **** | IFNA | Independent First Nations Alliance
| |
| **** | IFNA | International Federation of Netball Associations
| |
| **** | IFNA | International Federation of Nonlinear Analysis
| |
| **** | IFNA | International Federation of Nurse Anesthetists / Fédération Internationale des Infirmiers Anesthésistes
| |
| **** | IFNA | Interface Foundation of North America
| |
| *** | IFNA | Intermicronational Federation of News Agencies
| |
| *** | IFNA | inspiratory facial nerve activity
| |
| *** | IFNA | International Fitness Network Association
| |
| ** | IFNA | International Federation of Nonlinear Analysts
| |
| * | IFNA | International Federation of Nurse Anesthetists
| |
| * | IFNA | International Netball Federation
| |
| * | IFNA | International Federation of Nurse Anaesthetists
| |
| * | IFNA | FTSE Epra/Nareit North America Ishares (NASDAQ Stock Exchange [NASDAQ])
| |
| * | IFNA | International Federal of Nurse Anesthetists
| |
| * | IFNA | Intraoperative fine needle aspiration
| |
| * | IFNA | interferon A
| |
| * | IFNA | International FidoNet Association
| |