| Acronym | Meaning |
| ESP | Electrostatic Precipitator |
| DIN | Deutsche Industrie-Norm (German Industrial Standard) |
| HRV | Heart Rate Variability |
| DOS | Density Of States (in Band Structures) |
| LECD | Lifetime Equivalent Constant Dose |
| DEA | Drug Enforcement Administration |
| HST | Hubble Space Telescope |
| RHFR | Restricted Hartree-Fock-Roothaan |
| CISTI | Canadian Institute For Scientific And Technical Information |
| NDPD | National Data Processing Division |