RR

RR or rr may refer to:

Language

• rr (digraph)
• Revised Romanization of Korean, the official Korean language romanization system in South Korea
• Revised Romanization of Hangeul, the former official Hangeul language romanization system in South Korea

Medicine

• Relative risk, in statistics and epidemiology
• Respiratory rate, a vital sign
• A rhesus factor phenotype
• RR interval (R wave to R wave interval), the inverse of heart rate
• RR, abbreviation for blood pressure measurements taken with a sphygmomanometer invented by Scipione Riva-Rocci

Places

• Roraima, a state in Brazil

Organizations

• Rashtriya Rifles, an Indian counter-insurgency force
• Logo of Rekords Rekords, an American record label
• Royal Air Force (IATA airline designator)
• Logo of Richard Rohac Company, an Austrian art metal firm

Sports

• Rajasthan Royals, an Indian Premier League franchise
• Ranchi Rhinos, a defunct Hockey India League franchise

Technology

• Rapid Refresh, a short-range numerical weather prediction model
• Rear-engine, rear-wheel-drive layout, a term used in automotive technology
• Resource record, a term used in Domain Name System
• Round-robin scheduling, an algorithm for processes in an operating system

Transportation

• A predecessor of the R (New York City Subway service)
• Code for Regional Road, a class of road in Ontario (see County roads in Ontario#Glossary)
• An acronym for railroad
• Range Rover
• Rolls-Royce plc, LSE code and logo
  • Rolls-Royce (disambiguation) - most Rolls-Royce companies use RR logo

Entertainment

• RR (film), a 2008 experimental film by James Benning
• "Ren'ai Revolution 21", a song performed by Morning Musume
• Ruff Ryders Entertainment, a record label and East Coast rap collective
• Randy Rhoads (1956–1982), American guitarist

See also

• R&R (disambiguation)
• RRRR (disambiguation)
• RRR (disambiguation)
• R (disambiguation)