| 項目 |
| R |
| R. |
| R 因子［resistance factor］ |
| R-15［restricted-15］ |
| r. |
| RA1［Radiocommunication Assembly］ |
| RA2［rheumatoid arthritis］ |
| RA3［risk assessment］ |
| R.A.［Royal Academy］ |
| Ra［radium］ |
| rad（ラド）［radiation absorbed dose］ |
| rad.［radian］ |
| RAD-AR（レーダー）［RiskBenefit Assessment of Drugs-Analysis & Response］ |
| radar（レーダー）［radio detection and ranging］ |
| RAI（ライ）［(イ) Radio Televisione Italiano］ |
| RAID［Redundant Arrays of Inexpensive Disks］（レイド）⇒ディスク-アレイ |
| RAM（ラム）［random-access memory］ |
| RAND［Research and Development Corporation］ |
| R. & A.［Royal and Ancient Golf Club of St.Andrews］ |
| R & B［rhythm and blues］ |
| R & D［research and development］ |
| R & R［rock'n'roll］ |
| RAPCON（ラプコン）［radar approach control］ |
| RAPP（ラップ）［(ロ) Rossiiskaya Assotsiatsiya Proletarskikh Pisatelei］ |
| RAS（ラス）［remote access service］ |
| RB［running back］ |
| Rb［rubidium］ |
| RC1［reinforced concrete］ |
| RC2［remote control］ |
| R.C.［Red Cross］ |
| RC 構造［reinforced concrete construction］ |
| R.C.A.［Royal College of Art］ |
| RCC1［revised capital ratio］ |
| RCC2［Rock Climbing Club］ |
| RCU［respiratory care unit］ |
| RDB［relational database］ |
| RDF1［radio direction finder］ |
| RDF2［refuse-derived fuel］ |
| RDF3［Research & Development Fund］ |
| RDP［The reconstruction and development programme in new South Africa］ |
| RE1［rare earth elements］ |
| RE2［Reunion］ |
| RE3［reverse engineering］ |
| RE4［rotary engine］ |
| Re［rhenium］ |
| rec.［receipt］ |
| REIT［real estate investment trust］ |
| REM 睡眠［rapid eye movement sleep］ |
| rem（レム）［roentgen equivalent man］ |
| RENAMO［(ポルトガル) Resistencia Nacional Mocambicana］ |
| Rep.1［Representative］ |
| Rep.2［Republic］ |
| Rep.3［Republican］ |
| RETIO［Real Estate Transaction Improvement Organization］ |
| RF［right forward］ |
| rf［right fielder］ |
| RFP［rifampicin］ |
| R.F.U.［Rugby Football Union］ |
| RG［Varig Brazilian Airlines］ |
| RGB［red, green, blue］ |
| RGB 信号［red, green, blue signal］ |
| Rh［rhodium］ |
| Rh 因子［Rh factor; Rhesus monkey factor］ |
| Rh 式血液型［Rh blood group］ |
| RI1［radioisotope］ |
| RI2［Rehabilitation International］ |
| RI3［Rotary International］ |
| R.I.［Royal Institution］ |
| RIMPAC（リムパック）［Rim of the Pacific Exercise］ |
| RISC（リスク）［reduced instruction set computer］ |
| RLV［Reusable Launch Vehicle］ |
| RM1［reinforced masonry］ |
| RM2［risk management］ |
| RMB［Renminbi（人民幣）］ |
| RMR［relative metabolic rate］ |
| RMS1［recovery management support］ |
| RMS2［revised management scheme］ |
| Rn［radon］ |
| RNA［ribonucleic acid］ |
| RO［Romania］ |
| ROA1［recognized operating agency］ |
| ROA2［return on asset］ |
| ROE1［return on equity］ |
| ROE2［Rules of Engagement］ |
| ROI［return on investment］ |
| ROM1（ロム）［read-only memory］ |
| ROM2［Romania］ |
| ROR［Koror］ |
| ROSAT［Roentgen Obsavatory Satellite］ |
| RP1［Radio Press］ |
| RP2［red-purple］ |
| R.P.画［(フ) reproduction parfaite］ |
| RPF［Rwandan Patriotic Front］ |
| RPG［role-playing game］ |
| rpm, r.p.m.［revolutions per minute］ |
| R.P.R.［(フ) Rassemblement pour la Republique］ |
| RPS［retail price survey］ |
| RQ［respiratory quotient］ |
| RR1［rear engine rear drive］ |
| RR, R-R, R.R.2［Rolls-Royce］ロールス-ロイス。イギリスの高級乗用車。 |
| RRB［Radio Regulation Board］ |
| RS［remote sensing］ |
| R.S.［Royal Society］ |
| RSA［Republic of South Africa］ |
| RSC1［referee stop contest］ |
| RSC2［regional shopping center］ |
| R.S.C.［Royal Shakespeare Company］ |
| RSF［Ruble Stabilization Fund］ |
| RSI［repetitive strain injury］ |
| R.S.P.C.A.［Royal Society for the Prevention of Cruelty to Animals］ |
| RSV［Rous sarcoma virus］ |
| R.S.V.P., r.s.v.p.［(フ) Repondez s'il vous plait.］ |
| RSW［Fort Meyrs］ |
| RTC［Resolution Trust Corporation］ |
| RTGS［real-time gross settlement］ |
| RTOL（アールトール）［reduced takeoff and landing aircraft］ |
| RU［Russian Federation］ |
| Ru［ruthenium］ |
| RUS［Russian Federation］ |
| RV1［recreational vehicle］ |
| RV, R.V.2［Revised Version］改訂訳聖書。欽定（きんてい）訳聖書 （Authorized Version) の改訂訳で，新約は 1861 年，旧約は 85 年に出版された。 |
| RW［Republic of Rwanda］ |
| RWA［Republic of Rwanda］ |
| RWC［Real World Computing Project］ |
| RWD1［rear wheel drive］ |
| RWD2［rewind］ |
| Rx［(ラ) recipe］ |