| Acronym | Meaning |
| TDC | Top Dead Center |
| DWT | Discrete Wavelet Transform |
| LDR | Linear Dynamic Range |
| PAUR | Photochemical Activity And Solar Ultraviolet Radiation [project] |
| PEFC | Polymer Electrolyte Fuel Cell |
| HRS | Hazard Ranking System |
| QR-MWH | Quasi-relativistic Mulliken-Wolfsberg-Helmholz Method |
| MBE | Many-body Expansion (in Mol. Potential Energy Surface Calcn.) |
| SNUR | Significant New Use Rule |
| EMII | Enriched Mantle Component 2 (of S. R. Hart |