| MRO | master reference oscillator; medical review officer; minimal recognizable odor; muscle receptor orga... |
|---|---|
| NRS | neurobehavioral rating scale; normal rabbit serum; normal reference serum; numerical rating scale |
| NRSCC | National Reference System in Clinical Chemistry |
| ORS | olfactory reference syndrome; oral rehydration solution; oral surgery, oral surgeon; Orthopaedic Res... |
| OSI | open systems interconnection [reference model] |