| ICRS | Index Chemicus Registry System |
|---|---|
| NRCC | National Registry in Clinical Chemistry; National Research Council of Canada |
| NRM | National Registry of Microbiologists; normal range of motion; nucleus reticularis magnocellularis |
| OTR | Ovarian Tumor Registry; Occupational Therapist, Registered |
| RN | radionuclide; red nucleus; Registered Nurse; registry number; residual nitrogen; reticular nucleus |