Mr., an honorific title of men, see also Master . MR. may also refer to: · Places · Magyar Rádió, a Hungarian radio station · Mauritania country code · Menntaskólinn í Reykjavík, a secondary school in Iceland · People and organisations · Air Mauritania · Mahinda Rajapaksa, President of Sri Lanka · Master Replicas, a maker of prop replicas · Mathematical Reviews, a database of reviews of mathematics publications · Midland Railway · Mouvement Réformateur, a Belgian political party · MacRumors.com · Scientific terms · Mineralocorticoid receptor · Magnetic resonance · Magnetoresistance · Mental retardation, a developmental disorder · Mitral regurgitation, leaking of the mitral valve of the heart · Modified READ, a facsimi