(Main list of acronyms) R – (i) Reinforcing – Right – (s) Röntgen – (i) Restricted (movie rating) R0–9 R@R-(I) Respond as Receipt R0–99 – (i) R-value (insulation) R2I – (i) Resistance to Interrogation R3P – (i) Rearm, Refuel, and Resupply Point RA Ra – (s) Radium RA – (a) Radio Australia RA (i) Radio altimeter (s) Rain (METAR Code) (i) Rear Area Reinforced Alert Republican Army (i) Resolution advisory Right Ascension Royal Academy Royal Artillery (UK) RAA (a) Royal Automobile Association (i) Rear Assembly Area RAAF – (i) Royal Australian Air Force Rabobank – (p) Raiffeisen-Boerenleenbank (from the two banks that merged to form the modern company) RAC (i) Royal Automobile Club (in the United Kingdom, renamed RAC plc in 2002) Rutgers Athletic Center, an indoor arena at the New Brunswick–Piscataway campus of Rutgers University RACK – (a) Risk Aware Consensual Kink (SM phrase) Racon – (p) RAdar beaCON RADA – (a) Royal Academy of Dramatic Art Radar – (p) Radio Detection And Ranging RADB (i) Real America Database Resource Assessment Database Reunion Address DataBase Rice Allelopathy Data Base Routing Arbiter Database RADb – (i) Routing Assets Data Base RadB – (s) Rad51/Dmc1 homologous protein RADC – (i) Region Air Defence Commander RAE – (i) UK Royal Aircraft Establishment (−1991) RAF – (i) Red Army Faction – Royal Air Force RAG (a) Raising and Giving Rocket Antitank Grenade RAGBRAI – (a) Register's Annual Great Bicycle Ride Across Iowa RAM – (a) Random Access Memory – Rolling Airframe Missile – Royal Air Maroc Ramark – (p) RAdar MARKer RAOC – (i) Rear Area Operation Centre RAP (a/i) Radio Access Point Radiological Assistance Program (U.S. Department of Energy) Rear Area Protection Recognised [Operating/Operational] Air Picture Recurring Advance Payment Relational Associative Processor Reliable Acoustic Path Rocket-Assisted Projectile Rule against perpetuities RAPIDS – (a) Real-Time Automated Personnel Identification System (US Department of Defense personnel authentication system) RARDE – (a) UK Royal Armament Research and Development Establishment (1962–1991) RARE – (a) Rapid Acquisition with Relaxation Enhancement (MRI technique) RASC – (a) Royal Army Service Corp (former corps of British Army) RATELO – (p) Radiotelephone Operator RB Rb – (s) Rubidium RB – (i) Running Back (football) R&B – (i) Rhythm and Blues RBAR – (i) Row By Agonizing Row – a derogatory way of describing a technique of scanning a set of records in a database to update or examine the contents of each