MR

MR, Mr, mr, or mR may refer to:

• Mr. an honorific title of men

Arts and entertainment

• Mr. (artist), a Japanese artist
• MR (Marina and Rainer) (1989), a one-act chamber opera by Nikolai Korndorf
• Model Railroader, a US hobby magazine

Businesses and organizations

• Menntaskólinn í Reykjavík, the oldest junior college in Iceland.
• Air Mauritanie (IATA code)
• Master Replicas, a maker of prop replicas
• Metropolitan Railway, a London suburban railway
• Midland Railway, a United Kingdom railway
• Magyar Rádió, a Hungarian radio station
• Mouvement Réformateur, a Belgian political party

Language

• Marathi language (ISO 639-1 code "mr")
• McCune–Reischauer, a system of romanization of the Korean language

Law

• Master of the Rolls

Places

• Morocco country code (Library of Congress MARC standards)
• Martinique country code (World Meteorological Organization)
• Mauritania country code (ISO 3166-1 Alpha-2, FIPS 10-4)
  • .mr, the country code top level domain (ccTLD) for Mauritania
• Menntaskólinn í Reykjavík, a secondary school in Iceland

Science and technology

Biology and medicine

• Magnetic resonance imaging, a medical imaging technique
• Mendelian randomization, a way of using genetic information to estimate causal effects
• Mental retardation
• Mineralocorticoid receptor
• Mitral regurgitation of bloodflow in the heart

Computing

• .mr, the country code top level domain (ccTLD) for Mauritania
• Mixed reality, the merging of real and virtual worlds

Mathematics

• Mathematical Reviews, a journal and database

Physics

• Magnetoresistance, change in electrical resistance due to a magnetic field
• Magnetic resonance (disambiguation), a physical phenomenon with many applications
• Megarayleigh (MR), a unit of luminous flux
• Milliroentgen (mR), an obsolete unit of radioactive exposure

Transportation

• Nissan MR engine
• Rear mid-engine, rear-wheel-drive layout, an automotive layout

See also

• Mister (disambiguation)