| REG | radiation exposure guide; radioencephalogram, radioencephalography |
|---|---|
| REL | rate of energy loss; recommended exposure limit; resting expiratory level |
| RPEP | rabies post-exposure prophylaxis |
| SE | saline enema; sanitary engineering; side effect; smoke exposure; solid extract; sphenoethmoidal; spi... |
| STEL | short-term exposure limit |