| Acronym | Meaning |
| RIOSA | Rotational Infinite Order Sudden Approxn. |
| MESA | Mass Concentration Extinction Size Analyzer |
| FVRCI | Full Valence Rydberg Configuration Interaction |
| IAP | Inhibitor Of Apoptosis |
| CEUG | Continental Epeirogenic Uplift Granitoids |
| FACTS | Facilities And Company Tracking System |
| HAV | Hepatitis A Virus |
| EIA | Eikonal Impulse Approxn. (in Ion-atom Inelatic Collisions) |
| SARS | Scattering And Recoiling Spectrometry |
| DRI | Direct Reduced Iron |