R2

R2, R02, R.II, R.2 or R-2 may refer to:

Entertainment

• R2 (Rock'n'Reel), a British music magazine
• R2-D2, a character from Star Wars films and books, nickname R2
• Code Geass: Lelouch of the Rebellion R2, a 2008 anime series
• Resistance 2, a video game
• Relapse 2, a 2009 album by rapper Eminem
• Patricio Rey y sus Redonditos de Ricota or R2, an Argentine rock band
• Region 2, a DVD region code

Science and technology

• R² or r² (pronounced R-square), the coefficient of determination of a linear regression in statistics
• R², the two-dimensional real coordinate space in mathematics
• R2: Risk of explosion by shock, friction, fire or other sources of ignition, a risk phrase in chemistry
• R2 RNA element, a cis-acting element identified in R2 retrotransposons which is involved in priming the reverse transcription process
• ATC code R02 Throat preparations, a section of the Anatomical Therapeutic Chemical Classification System
• Haplogroup R2 (Y-DNA), a human Y-chromosome haplogroup
• receptor 2, the second in line of a series of cellular receptors, generally at the end of an acronym
• Gangrene (ICD-10 code)
• Robonaut 2, a NASA humanoid robotic development project
• R2 signalling, a family of telephony protocols for line and register signalling

Computing

• .r02, a RAR file extension
• Radare2, an open source reverse engineering framework also known as r2

Transportation

• R2 (Rodalies de Catalunya), a commuter rail line in Barcelona, Catalonia, Spain
• R2 (RER Vaud), an S-Bahn line in the canton of Vaud
• Wilmington/Newark Line (R2 Wilmington/Newark line)
• Warminster Line (R2 Warminster line)
• Radial Road 2 or R-2, an arterial road of Manila, Philippines
• Autopista Radial R-2, a Spanish radial motorway connecting Madrid to Guadalajara and passing through Alcobendas and connecting to N-320
• R2 expressway (Slovakia)
• R2 Marine Dr, an express bus route in Metro Vancouver, British Columbia, Canada
• R2 road (Zimbabwe), a road connecting Plumtree and Harare
• Orenburg Airlines (IATA code)

Vehicles

• R2, a sub-class of Group R rally cars
• DFW R.II, a 1918 German bomber aircraft
• Fiat R.2, a 1919 Italian reconnaissance aircraft
• HMS Zest (R02), a World War II British Royal Navy Z-class destroyer
• Jaguar R2, Jaguar Racing's car for the 2001 Formula One season
• Linke-Hofmann R.II, a World War I German bomber aircraft
• ORA R2, a Chinese electric city car
• Panzer 35(t), a Czech tank whose Romanian model was known as the R-2.
• Polikarpov R-2, a Soviet Union copy of the 1931 British Airco DH.9A light bomber aircraft
• Ross R-2 Ibis, a glider
• Subaru R2, a 2003 Japanese car
• USS R-2 (SS-79), a 1918 R-class coastal and harbor defense submarine of the US Navy

Other uses

• BBC Radio 2, a British radio station
• R-2 (missile), an improved version of German V-2 rocket manufactured by the Soviet Union
• R2 is a rank of United States research university in the Carnegie Classification of Institutions of Higher Education

See also

• Windows Server 2003 R2
• Windows Server 2008 R2
• SQL Server 2008 R2
• R–2R ladder, a resistor ladder