| Acronym | Meaning |
| SO | Stieltjes Orbitals (for Mol. Photoionization Continua) |
| ODT | Order-disorder Transition |
| AMAP | Arctic Monitoring And Assessment Program |
| OPAL | Omni-Purpose Apparatus At LEP |
| MIMS | Magnetic Field Induced Mixing Of Sublevels |
| APE | Aerosol Photoemission |
| PIO | Paired Interaction Orbital |
| OHC | Outer Hair Cell |
| AICS | Australian Inventory Of Chemical Substances |
| VPC | Vapor-phase Chromatography |