| R&B | Rhythm & Blues |
| R&B | Reed & Barton |
| R&D | Research and Development |
| R-Calif | Republican from California |
| R0 | Reproduction number |
| R0 | Record 0 |
| R143A | Trifluoroethane |
| RABMN | Remote Area Business Message Network |
| RAC | Rent A Car |
| RAC | Royal Agricultural College |
| RAC | Royal Automobile Club |
| RAC | Religious Action Center |
| RAC | Royal Armoured Corps |
| RAC | Reservation Against Cancellation |
| RAC | Recovery Audit Contractor |
| RAC | Rajasthan Armed Constabulary |
| RAC | Republic Aviation Corporation |
| RAC | Ryukyu Air Commuter |
| RADA | Royal Academy of Dramatic Art |
| RADA | Random Access Discrete Address |
| RADA | Rural Agricultural Development Authority |
| RADA | Remote Access Discovery Agent |
| RADA | Raleigh Area Development Authority |
| RADAR | RAdio Detection And Ranging |
| RADAR | Register of Australian Drug and Alcohol Research |
| RADAR | Royal Association for Disability Rights |
| RADAR | Rational Assessment of Drugs and Research |
| Radio | Orginated from wireless telegraphy |
| RAF | Royal Air Force |
| RAF | Rapid Action Force |
| RAF | Road Accident Fund |
| RAID | Redundant Array of Independent Disks |
| RAID | Rapid Aerostat Initial Deployment |
| RAJ | Rajkot Airport |
| RAK | Ras al-Khaimah |
| RAK | Ras Al Khaimah |
| RAK | Marrakech Menara Airport |
| RAK | Random Act of Kindness |
| RAK | Ramkot Railway Station |
| RAM | Random Access Memory |
| RAM | Royal Air Maroc |
| RAM | Rolling Airframe Missile |
| RAM | Royal Academy of Music |
| RAM | Residents Action Movement |
| RAMDAC | Random Access Memory Digital-to-Analog Converter |
| RAR | Roshal ARchive |
| RAR | Retinoic Acid Receptor |
| RAR | Royal Australian Regiment |
| RARP | Reverse Address Resolution Protocol |
| RAS | Remote Access Services |
| RAS | Renin-Angiotensin System |
| RAS | Russian Academy of Sciences |
| RAS | Reticular Activating System |
| RAS | Renal Artery Stenosis |
| RAS | Royal Astronomical Society |
| RAT | Remote Access Trojan |
| RAT | Rock Abrasion Tool |
| RAT | Ram Air Turbine |
| RAT | Raduzhny Airport |
| RAT | Router Audit Tool |
| RAW | RAW file format |
| RAW | Research and Analysis Wing |
| RaW | Radio Warwick |
| RAW | Read After Write |
| RAW | Rear Axle Weight |
| RAW | Arawa Airport |
| RBC | Red Blood Cell |
| RBG | Random Blood Glucose |
| RBG | Rhema Broadcasting Group |
| RBI | Reserve Bank of India |
| RBI | Risk Based Inspection |
| RBI | Raiffeisen Bank International |
| RBI | Ruđer Bošković Institute |
| RBI | Restaurant Brands International |
| RBI | Reviving Baseball in Inner Cities |
| RBI | Radio Berlin International |
| RBI | Relative Bearing Indicator |
| RBL | Real-time Blackhole List |
| RBL | Ratnakar Bank Limited |
| RBL | Royal British Legion |
| RBL | Rat Basophilic Leukemia |
| RBL | RasenBallsport Leipzig |
| RBL | Republic Bank Limited |
| RBL | Reasonable Benefit Limit |
| RBL | Rae Bareli Junction railway station |
| RBL | Reserve Based Lending |
| RBL | Ruthless by Law |
| RBL | Rifled Breech Loader |
| RBL | Rubber Band Ligation |
| RBL | Red Bluff Municipal Airport |
| RBL | Rogers Broadcasting Limited |
| RBL | Research Bureau Limited |
| RBS | Royal Bank of Scotland |
| RBS | Radio Base Station |
| RC | Radio Control |
| RC | Remote Control |
| RC | Release Candidate |
| RC | Reinforced Concrete |
| RC | Roman Catholic |
| RC | Registration Certificate |
| rc | Run Commands |
| RC | Resistor–Capacitor |
| RC | Runs Created |
| RC | Rivest’s Cipher/Ron’s Code |
| RC | Reconfigurable Computing |
| RC | Rubik’s Cube |
| RC | Royal Commission |
| RC | Roberto Carlos |
| RC | Atlantic Airways |
| RC | Relative Clause |
| RC | Research Chemical |
| RC | Reverse Circulation |
| RC | Roundcube |
| RC | Renaissance College |
| RC | Reflection Coefficient |
| RC | Ritchey–Chrétien |
| RC | Roanoke College |
| RC | Robert College |
| RC | Ridley College |
| RC | Riverside College |
| RC | Civil Revolution |
| RC | Revolutionary Council |
| RC | Re-Evaluation Counseling |
| RC | Richard Childress |
| RC | Royal Challengers |
| RC | RigidChips |
| RC | Rogers Centre |
| RCA | Radio Corporation of America |
| RCA | Royal College of Art |
| RCA | Root Cause Analysis |
| RCA | Radio Corporation of America |
| RCA | Reformed Church in America |
| RCA | Right Coronary Artery |
| RCB | Reinforced Concrete Box |
| RCB | Royal Challengers Bangalore |
| RCB | Robinson College of Business |
| RCB | Regional Centre for Biotechnology |
| RCB | Residual Current Breaker |
| RCB | Reims Champagne Basket |
| RCB | Richards Bay Airport |
| RCBS | Rajagiri Centre for Business Studies |
| RCBS | Kinmen Airport |
| RCBS | Rotary Club of Bangkok South |
| RCBS | River City Business Services |
| RCBS | Rathfarnham Concert Band Society |
| RCBS | Richard Campos Business Support |
| RCC | Renal Cell Carcinoma |
| RCC | Reinforced Cement Concrete |
| RCC | Roller-Compacted Concrete |
| RCC | Remote Center Compliance |
| RCC | Regional Cooperation Council |
| RCC | Riverside City College |
| RCC | Radio Common Carrier |
| RCC | Regional Cancer Centre |
| RCC | Radio-Controlled Clock |
| RCC | Ringing Choke Converter |
| RCC | Reinforced Carbon-Carbon |
| RCC | Rescue Co-ordination Centre |
| RCC | Roman Catholic Church |
| RCC | Radio College of Canada |
| RCC | Rockingham Community College |
| RCC | Rockland Community College |
| RCC | Rogue Community College |
| RCC | Roxbury Community College |
| RCC | Redcar Central |
| RCC | Region-Connection Calculus |
| RCC | River Continuum Concept |
| RCC | Revolutionary Command Council |
| RCC | Revolutionary Command Council |
| RCC | Revolutionary Command Council |
| RCC | Rachel Carson Center |
| RCC | Recompression Chamber |
| RCC | Recaredo Castillo College |
| RCC | Royal College of Chemistry |
| RCC | Royal College Curepipe |
| RCCB | Residual-Current Circuit Breaker |
| RCCB | Radiology Coding Certification Board |
| RCEP | Regional Comprehensive Economic Partnership |
| RCEP | Registered Clinical Exercise Physiologist |
| RCEP | Regional Centre for Educational Planning |
| RCEP | Royal Commission on Environmental Pollution |
| RCM | Reliability-Centered Maintenance |
| RCM | Royal College of Midwives |
| RCM | Royal Canadian Mint |
| RCM | Rotor Current Meter |
| RCM | Revenue Cycle Management |
| RCM | Ring-Closing Metathesis |
| RCM | Rapid Communications in Mass Spectrometry |
| RCM | Restrictive Cardiomyopathy |
| RCM | Royal College of Music |
| RCM | Royal Conservatory of Music |
| RCM | Reverse Cuthill–McKee |
| RCM | Regional County Municipality |
| RCM | Richmond Airport |
| RCM | Royal Cornwall Museum |
| RCM | Reciprocating Chemical Muscle |
| RCM | Rassemblement des citoyens et des citoyennes de Montréal |
| RCM | Regimental Corporal Major |
| RCMAS | Revised Children's Manifest Anxiety Scale |
| RCMAS | Rajagiri College of Management and Applied Sciences |
| RCPCH | Royal College of Paediatrics and Child Health |
| RCSC | Roman Catholic Syrian Christian |
| RCSC | Royal Civil Service Commission |
| RCSC | Red Cross Society of China |
| RCSC | Royal Charleroi Sporting Club |
| RCSC | Research Council on Structural Connections |
| RCSC | Royal Canadian Sea Cadets |
| RCSC | Retailing and Consumer Sciences |
| RCSC | Red Cliffs Secondary College |
| RCSC | Ryde Community and Sports Centre |
| RCT | Randomized Controlled Trial |
| RCT | Reverse Conducting Thyristor |
| RCT | RollerCoaster Tycoon |
| RCT | Rhondda Cynon Taf |
| RCT | Root Canal Treatment |
| RCT | Recitation |
| RCT | Royal Corps of Transport |
| RCT | Rose City Transit |
| RCT | Rural Community Transportation |
| RCT | Ritchey-Chrétien Telescope |
| RCT | Regimental Combat Team |
| RCx | Ramus Circumflexus |
| RCX | Robotic Command eXplorer |
| Rd | Road |
| RD | Recurring Deposit |
| RD | Reader’s Digest |
| RD | Retinal Detachment |
| RD | Registered Dietitian |
| Rd | Rutherford |
| RD | Real Drive |
| RD | Rilindja Demokratike |
| RD | Reservoir Dogs |
| RD | Rata Die |
| RD | Resident Director |
| RD | Reserve Decoration |
| RD | Radical Dreamers |
| RD | Rassemblement démocrate |
| RD | Ryan International Airlines |
| RD | Ram Dayalu Nagar railway station |
| RDBMS | Relational Database Management System |
| RDD | Random Digit Dialing |
| RDD | Resilient Distributed Dataset |
| RDD | Regime Disciplinar Diferenciado |
| RDD | Radiological Dispersal Device |
| RDD | Rassemblement pour la Démocratie et le Développement |
| RDD | Redding Municipal Airport |
| RDD | Regression Discontinuity Design |
| RDD | Responsibility-Driven Design |
| RDD | Rosai–Dorfman Disease |
| RDD | Radar Detector Detector |
| RDD | Rational Drug Design |
| RDD | Rural Development Department |
| RDD | Required Delivery Date |
| RDD | Replaceable Database Driver |
| RDD | Renault Driver Development |
| RDD | Rubber Duck Debugging |
| RDD | RDF Declarative Description |
| RDF | Resource Description Framework |
| RDO | Remote Data Objects |
| RDO | Rate-Distortion Optimization |
| RDO | Raster Document Object |
| RDO | Revenue Divisional Officer |
| RDO | Rural Development Organisation |
| RDRAM | Rambus Dynamic Random Access Memory |
| RDSC | Rakovski Defence and Staff College |
| RDSC | Reservoir District Secondary College |
| RDSO | Research Design and Standards Organisation |
| RDX | Research Department Explosive |
| Rebar | Reinforcing Bar |
| REC | Record |
| REC | Rural Electrification Corporation |
| REC | Renewable Energy Corporation |
| REC | Recruitment and Employment Confederation |
| REC | Recife/Guararapes–Gilberto Freyre International Airport |
| Red-Hat | from the red cap, the founder Marc Ewing use to wear |
| Redis | Remote Dictionary Server |
| Reebok | name comes from the Afrikaans spelling of rhebok, a type of African antelope |
| REET | Rajasthan Eligibility Examination for Teachers |
| REET | Real Estate Excise Tax |
| REET | Regional Environmental Emergency Team |
| Ref | Reference |
| REF | Rapid Equipping Force |
| REF | Row Echelon Form |
| REF | Research Excellence Framework |
| Regd | Registered |
| RegEx | Regular Expression |
| REM | Rapid Eye Movement |
| REM | Resource Efficiency Manager |
| rem | roentgen equivalent man |
| rem | Remainder |
| REML | Restricted Maximum Likelihood |
| REN | Ringer Equivalence Number |
| Renault | named after its founder, Louis Renault |
| Repo | Repository |
| repo | Repurchase Option |
| REPO | Remote Emergency Power Off |
| RER | Real Exchange Rate |
| RER | Réseau Express Régional |
| RER | Respiratory Exchange Ratio |
| RER | Base Aerea Del Sur Airport |
| RER | Rough Endoplasmic Reticulum |
| RERA | Real Estate Regulatory Act, 2016 |
| RERA | Real Estate Regulatory Authority |
| RERA | Real Estate Regulatory Agency |
| RERA | Respiratory Effort Related Arousal |
| RESS | REsponsive Web Design + Server Side Components |
| RESS | Ryerson Engineering Student Society |
| RESS | Rechargeable Energy Storage System |
| RESS | Rapid Expansion of Supercritical Solutions |
| RESTEC | Remote Sensing Technology Center of Japan |
| Retd | Retired |
| RETD | Renewable Energy Technology Deployment |
| Rev | Reverend |
| rev | Revolution |
| RF | Radio Frequency |
| RFA | RadioFrequency Ablation |
| RFA | Request For Application(s) |
| RFA | Radio Free Asia |
| RFA | Renewable Fuels Association |
| RFA | Royal Fleet Auxiliary |
| RFA | Radio Free Afghanistan |
| RFA | Rafaï Airport |
| rfa | Revit Family file |
| RFC | Request for Comments |
| RFC | Rangers Football Club |
| RFC | Radio-Frequency Choke |
| RFC | Regenerative Fuel Cell |
| RFC | Reconstruction Finance Corporation |
| RFC | Royal Flying Corps |
| RFC | Ramoji Film City |
| RFC | Racers for Christ |
| RFID | Radio Frequency IDentification |
| RFND | Resource For Native Development |
| RFP | Request For Proposal |
| RFP | Reversed-Field Pinch |
| RFP | Rocky Flats Plant |
| RFQ | Request for Quotation |
| RFQ | Radio-Frequency Quadrupole |
| RGB | Red-Green-Blue |
| RGGVY | राजीव गांधी ग्रामीण विद्युतीकरण योजना |
| RGJ | Reno Gazette-Journal |
| RGJ | Royal Golden Jubilee |
| RGJ | Royal Green Jackets |
| RGJ | Red Grape Juice |
| RGJ | Raw Garlic Juice |
| RGJ | Raiganj Railway Station |
| RGNIIPM | Rajiv Gandhi National Institute of Intellectual Property Management |
| RGNIYD | Rajiv Gandhi National Institute of Youth Development |
| RGPV | Rajiv Gandhi Proudyogiki Vishwavidyalaya |
| RGUHS | Rajiv Gandhi University of Health Sciences |
| RH | Relative Humidity |
| RH | Red Hat |
| RH | Restoration Hardware |
| Rh | Rhesus factor |
| Rh | Rhodium |
| RH | Republic Express Airlines |
| RH | Redhill postcode area |
| RH | Ryan’s Hope |
| RH | Releasing Hormone |
| RHB | Right Handed Batsman |
| RHB | Rajasthan Housing Board |
| RHB | Rashid Hussein Bank |
| RhB | Rhätische Bahn |
| RHB | Royal Hawaiian Band |
| RHCE | Red Hat Certified Engineer |
| RHCE | Red Hill Creek Expressway |
| RIB | Rigid-Inflatable Boat |
| RIB | Routing Information Base |
| RIB | Romanian International Bank |
| RIB | Roman Inscriptions of Britain |
| RIB | Riberalta Airport |
| RIB | Relevé d’Identité Bancaire |
| RIB | Retirement Insurance Benefits |
| RiB | Razed in Black |
| RIB | Renderman Interface Bytestream |
| RIL | Reliance Industries Limited |
| RIL | Radio Interface Layer |
| RIL | Garfield County Regional Airport |
| RIL | Radar Innovations Laboratory |
| RIM | Research In Motion |
| RIM | Reaction Injection Molding |
| RIMC | Rashtriya Indian Military College |
| RIP | Requiescat In Pace |
| RIP | Routing Information Protocol |
| RIP | Raster Image Processor |
| RIP | Regulation of Investigatory Powers |
| RIP | Refractive Index Profile |
| RiP | Rock im Park |
| RIR | Regional Internet Registry |
| RISC | Reduced Instruction Set Computer |
| RIT | Rochester Institute Of Technology |
| RIT | Rajiv Gandhi Institute of Technology |
| RIT | Rio Tigre Airport |
| RIT | Rourkela Institute of Technology |
| RJ | Radio Jockey |
| RJ | Registered Jack |
| RJ-11 | Registered Jack type 11 |
| RJ-45 | Registered Jack type 45 |
| RJIL | Reliance Jio Infocomm Limited |
| RK | Radial Keratotomy |
| RKCL | Rajasthan Knowledge Corporation Limited |
| RKFI | Raaj Kamal Films International |
| RKGEC | Raj Kumar Goel Engineering College |
| RKGIT | Raj Kumar Goel Institute of Technology |
| RKM | Route Kilometer |
| RKM | Runge Kutta Methods |
| RKM | Ramakrishna Mission |
| RKM | Raja Ki Mandi Railway Station |
| RKM | Religious Kibbutz Movement |
| RKVY | राष्ट्रीय कृषि विकास योजना |
| RLA | Rated Load Amperes |
| RLA | Railway Labor Act |
| RLEK | Rural Litigation and Entitlement Kendra |
| RLS | Restless Leg Syndrome |
| RLS | Recursive Least Squares |
| RLWL | Remote Location Wait List |
| RMA | Return Merchandise Authorization |
| RMA | Roma Airport |
| RMA | Royal Military Academy |
| RMA | Randolph-Macon Academy |
| RMA | Riverside Military Academy |
| RMA | Rubin Museum of Art |
| RMA | Royal Military Academy |
| RMA | Ramon Magsaysay Award |
| RMB | 人民币 |
| RMB | Rand Merchant Bank |
| RMB | Right Mouse Button |
| RMB | Real Madrid Baloncesto |
| RMB | Rocky Mountain BASIC |
| RMB | Restaurant Miniature Buffet |
| RMB | Rocky Mountain Bicycles |
| RMB | Rødovre Mighty Bulls |
| RMB | Roadside Mail Box |
| RmKV | Rm.K.Viswanatha Pillai |
| RMPL | Reactive Model-based Programming Language |
| RMPL | Ramu Machinery Private Limited |
| RMPL | Rocky Mountain Philatelic Library |
| RMS | Root Mean Square |
| RMS | Royal Mail Ship |
| RMS | Rhabdomyosarcoma |
| RMS | Rostral Migratory Stream |
| RMS | Rate-Monotonic Scheduling |
| RMS | Reconfigurable Manufacturing System |
| RMS | Record Management System |
| RMS | Rights Management Services |
| RMS | Royal Microscopical Society |
| RMS | Richard Matthew Stallman |
| RMS | Roads & Maritime Services |
| RMS | Ramstein Air Base |
| RMS | Ramanujan Mathematical Society |
| RMS | Royal Medical Society |
| RMS | named after the musicians: Ray Russell, Mo Foster & Simon Phillips |
| RMS | Russian Mineralogical Society |
| RMS | Rotana Media Services |
| RMS | Reims Management School |
| RMS | Railway Mail Service |
| RMS | Republik Maluku Selatan |
| RMS | Railway Mail Service |
| RMS | Radnor Middle School |
| RMS | Robert May’s School |
| RMS | Regroupement des Militants Syndicaux |
| RMS | Richland Middle School |
| RMS | Romulus Middle School |
| RMS | Rambhakta Memorial School |
| RMW | Read-Modify-Write |
| RMW | Regulated Medical Waste |
| RMW | Radius of Maximum Wind |
| RMW | Regional Municipality of Waterloo |
| RNA | Ribonucleic Acid |
| RNA | Research Natural Area |
| RNA | Royal Nepalese Army |
| RNA | Nepal Airlines |
| RNA | Religion Newswriters Association |
| RnD | Research and Development |
| RND | RedaktionsNetzwerk Deutschland |
| RND | Radical Neck Dissection |
| RND | Reflex Neurovascular Dystrophy |
| RND | Rassemblement National pour la Démocratie |
| RND | Democratic National Rally |
| RND | Railroads for National Defense |
| RNI | Rate of Natural Increase |
| RNI | Registrar of Newspapers for India |
| RNI | Reference Nutrient Intake |
| RNI | Radio North Sea International |
| RNI | Redwood Neuroscience Institute |
| RNTCP | Revised National Tuberculosis Control Program |
| RO | Romania |
| RO | Reverse Osmosis |
| RO | Ragnarok Online |
| RO | Radiation Oncology |
| ro | Romania |
| RO | Renal Osteodystrophy |
| ROAS | Return On Advertising Spend |
| ROAS | Router On A Stick |
| ROC | Republic of China |
| ROC | Registrar of Companies |
| ROC | Registrar of Companies |
| ROC | Return On Capital |
| ROC | Rate Of Change |
| ROC | Receiver Operating Characteristic |
| ROC | Radius Of Curvature |
| ROC | Radius Of Curvature |
| ROC | Russian Orthodox Church |
| RoC | Reign of Chaos |
| ROC | Greater Rochester International Airport |
| ROC | Rest of Canada |
| ROC | Royal Observer Corps |
| ROC | Rise of Cobra |
| ROC | Recovery-Oriented Computing |
| ROC | Rest of Canada |
| Roche | from the name of its founder, Fritz Hoffmann-La Roche |
| ROFL | Rolling On Floor Laughing |
| ROFL | Rolling on the Floor Laughing |
| ROFLMAO | Rolling On Floor Laughing My A** Off |
| RoHS | Restriction of Hazardous Substances |
| ROI | Return On Investment |
| ROI | Region Of Interest |
| ROI | Release Of Information |
| ROI | Republic of Ireland |
| ROI | Roi Et Airport |
| RoI | Rate of Interest |
| ROI | Royal Institute of Oil Painters |
| ROI | Republic of India |
| RoI | Republic of Indonesia |
| ROLF | Rolling on the Floor Laughing |
| Rolls-Royce | from the name of its founders, Charles Rolls and Henry Royce |
| ROM | Read-Only Memory |
| ROM | Royal Ontario Museum |
| RoM | Runes of Magic |
| ROM | Risk Of Mortality |
| ROM | Rupture Of Membranes |
| ROM | Refuel On the Move |
| ROM | Return On Margin |
| ROM | RFID On Metal |
| RON | Romanian leu |
| RON | Run of Network |
| RON | Research Octane Number |
| RON | Nauru Airlines |
| RoN | Rise of Nations |
| RON | Rona Inc. |
| RON | Resilient Overlay Network |
| RONW | Return on Net Worth |
| ROR | Rate Of Return |
| ROR | Ruby on Rails |
| ROR | Roman Tmetuchl International Airport |
| ROTFL | Rolling On The Floor Laughing |
| ROYGBIV | Red, Orange, Yellow, Green, Blue, Indigo, Violet |
| RPET | Recycled Polyethylene Terephthalate |
| RPET | Rajasthan Pre-Engineering Test |
| RPF | Railway Protection Force |
| RPF | Rwandan Patriotic Front |
| RPF | Reverse Path Forwarding |
| RPF | Renal Plasma Flow |
| RPF | Registered Professional Forester |
| RPF | Rassemblement pour la France |
| RPF | Real Person Fiction |
| RPF | Retroperitoneal Fibrosis |
| RPF | Rehabilitation Project Force |
| RPF | Rassemblement du Peuple Français |
| RPF | Reformatorische Politieke Federatie |
| RPF | Radioisotope Production Facility |
| RPF | Raspberry Pi Foundation |
| RPF | Reverse Power Feeding |
| RPG | Role-playing Game |
| RPG | Rebounds Per Game |
| RPG | Rocket-propelled Grenade |
| RPLI | Rural Postal Life Insurance |
| rpm | Revolutions Per Minute |
| RPM | Revenue Per Mille |
| RPM | RPM Package Manager |
| RPM | Resale Price Maintenance |
| RPM | Ngukurr Airport |
| RPM | Raised Pavement Marker |
| RPM | Re-Punched Mint Mark |
| RPM | Revenue Passenger Mile |
| RPN | Reverse Polish Notation |
| RPN | Radio Philippines Network |
| RPN | Registered Psychiatric Nurse |
| RPN | Risk Priority Number |
| RPN | Rosh Pina Airport |
| RPS | Redundant Power Supply |
| RPS | Rock Paper Scissors |
| RPS | Richmond Public Schools |
| RPS | Royal Philatelic Society |
| RPS | Royal Photographic Society |
| RPS | Renewable Portfolio Standard |
| RPS | Royal Pharmaceutical Society |
| RPS | Reform Party of Syria |
| RPS | Rutgers Preparatory School |
| RPS | Rubber Producers Society |
| RPS | Rulang Primary School |
| RPS | Research Publishing Services |
| RPS | Rosanna Primary School |
| RPSC | Rajasthan Public Service Commission |
| RPSC | Raytheon Polar Services Company |
| RPSC | Royal Philatelic Society of Canada |
| RPSL | RealNetworks Public Source License |
| RPSL | Routing Policy Specification Language |
| RPSL | Royal Philatelic Society London |
| RPSL | Recruitment and Placement Services Licence |
| RQWL | Request Wait List |
| RRB | Railroad Retirement Board |
| RRB | Regional Rural Banks |
| RRB | Railway Recruitment Board |
| RREP | Route Reply |
| RREP | Respiratory-Related Evoked Potential |
| RREQ | Route Request |
| RRN | Relative Record Number |
| RRN | Rural Reconstruction Nepal |
| RRP | Recommended Retail Price |
| RRP | Retail Ready Packaging |
| RRP | Recurrent Respiratory Papillomatosis |
| RRP | Radical Retropubic Prostatectomy |
| RRP | Radio Reconnaissance Platoon |
| RRR | Rate of Return |
| RRR | Residual-Resistance Ratio |
| RRR | Required Reserve Ratio |
| RRR | Relative Risk Reduction |
| RRR | Risk Retention Reporter |
| RRR | Raroia Airport |
| RRR | Reduce, Reuse, Recycle |
| RRR | Reverse Repo Rate |
| Rs | Rupee |
| RS | Serbia |
| RS | Recommended Standard |
| RS | Remote Sensing |
| rs | Serbia (TLD) |
| RS | République Solidaire |
| RS | Roemheld Syndrome |
| RS | Roberval & Saguenay |
| RS | Rio Grande do Sul |
| RS | Rajya Sabha |
| RS-232 | Recommended Standard 232 |
| RSA | Republic of South Africa |
| RSA | Retirement Savings Account |
| RSA | Rehabilitation Services Administration |
| RSA | Santa Rosa Airport |
| RSA | Road Safety Audit |
| RSA | Respiratory Sinus Arrhythmia |
| RSA | Royal and Sun Alliance |
| RSA | Renaissance Society of America |
| RSA | Remote Supervisor Adapter |
| RSA | Redstone Arsenal |
| RSA | Retirement Systems of Alabama |
| RSBY | राष्ट्रीय स्वास्थ्य बीमा योजना |
| RSE | Relative Standard Error |
| RSE | Relationships and Sexuality Education |
| RSE | Rose Bay Airport |
| RSE | Royal Society of Edinburgh |
| RSE | Red Storm Entertainment |
| RSE | Rhymesayers Entertainment |
| RSE | Ramtha’s School of Enlightenment |
| RSET | Required Safe Egress Time |
| RSET | Rajagiri School of Engineering & Technology |
| RSET | Rod Surface-Elevation Table |
| RSFSR | Soviet Federated Socialist Republic |
| RSI | Relative Strength Index |
| RSI | Repetitive Strain Injury |
| RSI | RADARSAT International |
| RSI | Review of Scientific Instruments |
| RSI | Research Science Institute |
| RSI | Regional Snowfall Index |
| RSI | Rapid Sequence Induction |
| RSI | RadioTelevisione Svizzera di lingua Italiana |
| RSI | Radio Singapore International |
| RSI | Radiofrequency Safety International |
| RSI | Relational Semantics, Inc. |
| RSi | Radio Slovenia International |
| RSI | Red Sport International |
| RSI | Robotics Society of India |
| RSJ | Rolled Steel Joist |
| RSJ | Robotics Society of Japan |
| RSJ | Rosario SPB Airport |
| RSJ | Rock Street Journal |
| RSRTC | Rajasthan State Road Transport Corporation |
| RSS | Rich Site Summary |
| RSS | राष्ट्रीय स्वयंसेवक संघ |
| RSS | Residual Sum of Squares |
| RSS | Resident Set Size |
| RSS | Royal Statistical Society |
| RSS | Russell–Silver Syndrome |
| RSS | Recombination Signal Sequences |
| RSS | Reactive Sulfur Species |
| RSS | Radio Service Software |
| RSTV | Rajya Sabha TV |
| RSVP | Répondez S’il Vous Plaît |
| RSVP | Resource Reservation Protocol |
| RSVP | Rare Symmetry Violating Processes |
| RSVP | Rapid Serial Visual Presentation |
| RSVY | Rashtriya Sam Vikas Yojana |
| RSWL | Road Side Waiting List |
| RT | Russia Today |
| RT | Retweet |
| RT | Room Temperature |
| RT | Radiation Therapy |
| RT | Reaction Time |
| RT | Reverse Transcriptase |
| RT | Rotten Tomatoes |
| RT | Richard Thompson |
| RT | Request Tracker |
| RT | Ruby Tuesday Inc. |
| RT | Ralink Technology |
| RT | Reproductive Technology |
| RT | Radio Times |
| RTA | Ready-to-assemble |
| RTA | Road Traffic Accident |
| RTA | Restricted to Adults |
| RTA | Royal Thai Army |
| RTC | Real Time Clock |
| RTC | Regional Trial Court |
| RTC | Réseau de Transport de la Capitale |
| RTC | Residential Treatment Center |
| RTC | Real-Time Communication |
| RTC | Recruit Training Command |
| RTC | Renton Technical College |
| RTC | Royal Thimphu College |
| RTC | Radiotelevisão Caboverdiana |
| RTC | Dirección General de Radio, Televisión y Cinematografía |
| RTC | Religious Technology Center |
| RTC | Resolution Trust Corporation |
| RTC | Rails-to-Trails Conservancy |
| RTC | Regional Transportation Commission of Southern Nevada |
| RTC | Regional Transportation Commission of Washoe County |
| RTC | Road Traffic Collision |
| RTC | Road Transport Corporation |
| RTC | Reston Town Center |
| RTC | Rotterdam Terror Corps |
| RTC | Rail Traffic Controller |
| RTC | Redmond Town Center |
| RTC | Reformed Theological College |
| RTC | Railway Technical Centre |
| RTC | Regional Technical Colleges |
| RTC | Rochester Telephone Corporation |
| RTET | Rajasthan Teacher Eligibility Test |
| RTGS | Real-Time Gross Settlement |
| RTGS | Royal Thai General System of Transcription |
| RTI | Right To Information |
| RTI | Response to Intervention |
| RTI | Runtime Infrastructure |
| RTI | Radio Taiwan International |
| RTI | Respiratory Tract Infection |
| RTI | Research Triangle Institute |
| RTL | Register-Transfer Level |
| RTL | Right-To-Left |
| RTL | Run-Time Library |
| RTL | Ride the Lightning |
| RTM | Released To Manufacturing |
| RTM | Radio Televisyen Malaysia |
| RTM | Rotterdam The Hague Airport |
| RTMNU | Rashtrasant Tukadoji Maharaj Nagpur University |
| RTO | Regional Transport Office |
| RTO | Recovery Time Objective |
| RTO | Rent-To-Own |
| RTO | Registered Training Organisation |
| RTO | Regional Transmission Organization |
| RTO | Regenerative Thermal Oxidizer |
| RTO | Retired Teachers of Ontario |
| RTO | Regional Transport Officer |
| RTO | Rejected Take-Off |
| RTO | Really Terrible Orchestra |
| RTOS | Real-Time Operating System |
| RTOS | Rochester Theater Organ Society |
| RTP | Real-time Transport Protocol |
| RTP | Research Triangle Park |
| RTP | Rapid Thermal Processing |
| RTP | Rally of the Togolese People |
| RTP | Royal Thai Police |
| RTS | Real-Time Strategy |
| RTS | Radio Télévision Suisse |
| RTS | Request to Send |
| RTS | Radio Television of Serbia |
| RTS | Radiodiffusion Télévision Sénégalaise |
| RTS | Royal Television Society |
| RTS | Rapid Transit Series |
| RTS | Russian Trading System |
| RTSP | Real Time Streaming Protocol |
| RTSP | Research Triangle Schools Partnership |
| RUB | Russian Ruble |
| RUB | Ruhr University Bochum |
| RUB | Rich Urban Biker |
| RUB | Royal University of Bhutan |
| RUB | Road Under Bridge |
| RUB | Recording Unit Block |
| RUB | Relocatable User Backup |
| RUB | Rubicor Group Limited |
| RubSIS | Rubber Soil Information System |
| Ruby | named after the precious gemstone, Ruby |
| RUDA | Rajkot Urban Development Authority |
| RUIM | Removable User Identity Module |
| RUM | Real User Monitoring |
| RuPay | Rupee + Payment |
| RUPD | Rear Underride Protection Device |
| RUPD | Rutgers University Police Department |
| RUPD | Rice University Police Department |
| RUPD | Radford University Police Department |
| RUSA | Reference and User Services Association |
| RUSA | Randonneurs USA |
| RUSA | राष्ट्रीय उच्चतर शिक्षा अभियान |
| RUSA | Rutgers University Student Assembly |
| RV | Recreational Vehicle |
| RV | Residual Volume |
| RV | Random Variable |
| RV | Research Vessel |
| RV | Revised Version |
| RV | Radio Vaticana |
| RV | Rashtreeya Vidyalaya |
| RV | Rožňava |
| RV | Radial Velocity |
| RV | Air Canada Rouge |
| RV | Rahway Valley Railroad |
| RV | Relative Value |
| RV | Remote Viewing |
| RV | Rød Valgallianse |
| RV | Richard VanGrunsven |
| RV | Registered Voters |
| RV | Ryom Verzeichnis |
| RV | Revenue Village |
| Rv | Riksvei/Riksveg |
| RVCE | Rashtreeya Vidyalaya College of Engineering |
| RVCJ | Rajnikant Versus CID Jokes |
| RVSP | Right Ventricular Systolic Pressure |
| RVSP | Reverse Vertical Seismic Profiling |
| RWD | Rear Wheel Drive |
| RWD | Responsive Web Design |
| RWD | Red Water Disease |
| RWD | RwandAir |
| RWD | Reward Minerals Limited |
| RWDSU | Retail, Wholesale and Department Store Union |
| Rx | Prescription |
| Rx | Receive/Receiver/Reception |
| RX | Radio/Receiver |
| RX | Regent Airways |
| RX | Radiant Crossover |
| RX | Rocket eXperimental |
