RSA
- Alcohol server training
- New Hampshire Revised Statutes Annotated
- OTs-01 Kobalt
- Pragmatics
- RSA (cryptosystem)
- RSA (missile)
- RSA Conference
- RSA Factoring Challenge
- RSA Insurance Group
- RSA Security
- RSA numbers
- Rabbinical Seminary of America
- Rational Software Architect
- Ray Steadman-Allen
- Redstone Arsenal
- Regional Science Association International
- Rehabilitation Services Administration
- Remote supervisor adapter
- Renaissance Society of America
- Repressive state apparatuses
- Respiratory sinus arrhythmia
- Retirement Systems of Alabama
- Retrosynthetic analysis
- Revenu de solidarité active
- Rhetoric Society of America
- Ridley Scott Associates
- Road Safety Authority
- Roentgen stereophotogrammetry
- Root
- Royal New Zealand Returned and Services' Association
- Royal School of Artillery
- Royal Scottish Academy
- Royal Serbian Army
- Royal Signals Association
- Royal Society of Arts
- Rsa RNA
- Runway safety area
- Russian Ski Association
- Santa Rosa Airport (Argentina)
- South Africa