| Acronym | Meaning |
| SPP | Suspended Particulate Phase |
| SLE | Stochastic Liouville Equation (in Quantum Statistical Mechanics) |
| SSIS | Scanning Surface Inspection System |
| CFBR | Conventional Fluidized Bed Reactor |
| AGB | Asymptotic Giant Branch (stars) |
| SLMO | Strictly Localized Molecular Orbital |
| SCC | Source Classification Code |
| AQCC | Air Quality Control Center |
| NWC | National Water Council (UK) |
| OWEC | Office Of Wastewater Enforcement And Compliance |