| Acronym | Meaning |
| ID | Isotope Dilution |
| PZC | Polyzirconium Compound (isopropyl Alc.-zirconium Chloride Copolymer) |
| WIC | Washington Information Center |
| BCKD | Branched-chain Alpha-ketoacid Dehydrogenase |
| EERL | Eastern Environmental Research Laboratory |
| ACPTQ | Approx. Coupled Pair (theory Cor. For Connected) Triple And Quadruple Excitations |
| IAHE | International Association For Hydrogen Energy |
| RAM | Reference-system Average Mayer-function (in Perturbation Theory) |
| RNAI | RNA Interference |
| OPW | Orthogonalized Plane Wave |