| Acronym | Meaning |
| AMPTE | Active Magnetosphere Particle Tracer Explorers |
| NCAT | National Catalog Database (accessible Through OLS) |
| NASQAN | National Stream Quality Accounting Network |
| ACA | American Crystallographic Association |
| NTTAA | National Technology Transfer And Advancement Act |
| SBE | Single Base Extension |
| HOC | Halogenated Organic Carbons |
| CCS | Classical Centrifugal Sudden (in Calcns. On Reactions) |
| CIR | Cylindrical Internal Reflection |
| RS | Rayleigh Schroedinger (perturbation Theory) |