| Acronym | Meaning |
| OPE | Operator Product Expansion |
| PACAP | Pituitary Adenylate Cyclase-activating Polypeptide |
| CIPEA | Comite International Pour L'Etude Des Argiles |
| BRC | Basic Regulatory Control |
| NIWA | National Institute For Water And Atm. Research [New Zealand] |
| SWRRB | Simulation For Water Resources In Rural Basins |
| ECT | Emission-Computed Tomography |
| CEPA-VAR | Coupled-electron-pair Approxn.-variational |
| VLTI | Very Large Telescope Interferometer |
| PEXAFS | Photoemission Extended X-ray Absorption Fine Structure |