| Abbreviation | Definition |
|---|---|
| RLCI | Receive Line Clock Input |
| RLDI | Receive Line Data Input |
| RLF | Remote Line Failure |
| RLTT | Rawafed Libya for Telecommunications and Technology |
| RLU | Remote Line Unit |
| RM | Resource Management |
| RMTN | Regional Meteorological Telecommunication Network |
| RNC | Radio Network Controller |
| RNR | Receive Not Ready |
| RNU | Reliability Network Upgrade |
| RNW | Radio NetWork |
| RNX | Restricted Numeric Exchange |
| RO | Recieve Only |
| ROF | Reformat On the Fly |
| ROH | Receiver Off Hook |
| ROI | Return On Information |
| ROI | Return On Internet |
| ROL | Rectifying Operating Line |
| ROP | Result Output Period |
| ROPP | Receiver Only Packet Pair |