| Acronym | Meaning |
| GX | Generalized Exchange |
| OPPTS | Office For Prevention |
| MDR | Multidrug Resistance |
| PWBA-R | Plane-wave Born Approxn. With Relativistic Effects |
| ASM | Acoustic Surface Measurement |
| PAFC | Phosphoric Acid Fuel Cells |
| AAQS | Ambient Air Quality Standard (USEPA) |
| DMCC | Dimethylcarbamyl Chloride |
| PCNA | Proliferating Cell Nuclear Antigen |
| NDDN | National Dry Deposition Network (US EPA) |