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 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) 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),