| PSIL | preferred frequency speech interference level |
|---|---|
| PTL | peritoneal telencephalic leukoencephalomyopathy; pharyngotracheal lumen; plasma thyroxine level post... |
| REL | rate of energy loss; recommended exposure limit; resting expiratory level |
| RL | radial line; radiation laboratory; reduction level; renal dysplasia-limb defects [syndrome]; resisti... |
| sAl | serum aluminum [level] |