| R&D | Research & Development |
| R&R | Rest & Relaxation |
| RAT | Remotely Activated Trojan |
| RB@Ya | Right Back at Ya |
| RBAY | Right Back At You |
| RBTL | Read Between The Lines |
| RC | Remote Control |
| RCI | Rectal Cranial Inversion |
| RE | Regards -or- Reply -or- Hello Again |
| RFD | Request For Discussion |
| RFR | Really F***ing Rich |
| RFS | Really F***ing Soon |
| RGR | Roger |
| RIYL | Recommended If You Like |
| RKBA | Right to Keep and Bear Arms |
| RL | Real Life |
| RLF | Real Life Friend |
| RM | Remake |
| RMLB | Read My Lips Baby |
| RMMA | Reading My Mind Again |
| RMMM | Read My Mail Man |
| RN | Right Now |
| ROFL | Rolling On Floor Laughing |
| ROR | Raffing Out Roud (in scooby-doo dialect) |
| ROTFL | Rolling On The Floor Laughing |
| ROTFLMAO | Rolling On The Floor Laughing My Ass Off |
| ROTFLOL | Rolling On The Floor Laughing Out Loud |
| ROTGL | Rolling On The Ground Laughing |
| ROTGLMAO | Rolling On The Ground Laughing My Ass Off |
| ROTM | Right On The Money |
| RPG | Role Playing Games |
| RRR | haR haR haR (instead of LOL) |
| RSN | Real Soon Now |
| RT | Real Time |
| RTBS | Reason To Be Single |
| RTFAQ | Read the FAQ File |
| RTFM | Read The F***ing Manual |
| RTFQ | Read The F***ing Question |
| RTK | Return To Keyboard |
| RTM or RTFM | Read The Manual -or- Read The F***ing Manual |
| RTTSD | Right Thing To Say Dude |
| RU | Are You? |
| RU/18 | Are You Over 18? |
| RUFKM | Are You F***ing Kidding Me? |
| RUH | Are You Horny? |
| RUMCYMHMD | Are You on Medication Cause You Must Have Missed a Dose |
| RUMORF | Are You Male OR Female? |
| RUNTS | Are You Nuts? |
| RUOK | Are You OK? |
| RUS | Are You Serious? |
| RUSOS | Are You SOS (in trouble)? |
| RUT | Are You There? |
| RUUP4IT | Are You Up For It? |
| RX | Regards |
| RYO | Roll Your Own |
|
