| Abbreviation | Definition |
|---|---|
| RITD-HBT | Resonant Interband Tunnel Diode - Heterojunction Bi-polar Transistor |
| RJ | Registered Jack |
| RKKY | Ruderman-Kittel-Kasuya-Yoshida |
| RL | Load Resistance |
| RL | Return Loss |
| RLA | Rated Load Amperes |
| RLC | Rated Load Current |
| RLC | Rear Left Channel |
| RLC | Run Length Coding |
| RLE | Research Laboratory of Electronics |
| RLE | Research Laboratory of Electronics at MIT |
| RLE | Windows or CompuServe RLE image format |
| RLI | Resist LIthography |
| RLSA | Radial Line Slot Antenna |
| RLSD | Receive Line Signal Detect |
| RLTF | Reliability Lifetime Tradeoff Framework |
| RLY | Relay |
| RLZ | Run Level Zero |
| RMA | Robust Multichip Analysis |
| RMA | Rosin Mildly Activated |