| Abbreviation | Definition |
|---|---|
| R | Reliability |
| R | Resistance |
| R2R | Run-To-Run |
| RA | Random Amplitude |
| RA | Rosin Activated |
| RAC | RAMBUS ASIC (Application Specific Integrated Circuit) Cell |
| RAC | Remote Access and Control |
| RACER | Rescue Alarm Contain Extinguish Relocate |
| RACHEL | Royal Alexandra Cardiovascular Health Electronic Links |
| RADAR | RAdio Detection And Ranging |
| RAE | Residue After Evaporation |
| RAEC | Russian Association for Electronic Communications |
| RAF | Random Access File |
| RAIRS | Reflection-Absorption InfraRed Spectroscopy |
| RAMDAC | Random Access Memory Digital-to-Analog Converter |
| RAMP | Reliability Analysis and Modeling Program |
| RAMS | Reliability, Availability, Maintainability, and Supportability |
| RAP | Radio Activated and Programmable |
| RAP | Relay Access Probe |
| RAP | Reliability Assessment Prediction |