| Acronym | Meaning |
| TER | Total External Reflection |
| GS | Gelius-Siegbahn (MO Approxn.) |
| CCA | Coupled-cluster Approach |
| PAO | Pseudo-atomic Orbital |
| CTC | Control Technology Center |
| HT-EOVC | High-temperature Engine Oil Viscosity Classification |
| AERC | Association Of Ecosystem Research Centers |
| GSAM | Generalized Standard Addition Method |
| BHTV | Borehole Televiewers |
| SLPM | Standard Liters Per Minute |