| Abbreviation | Definition |
|---|---|
| SKT | South Korea Telecom |
| SKT | Sun Kyung Telecom |
| SL | Single Line |
| SLC | Service Level Contract |
| SLC | Subscriber Line Concentrator |
| SLC | Subscriber Loop Carrier |
| SLIC | Subscriber Line Interface Circuit |
| SLICE | Selective Line Insertion Communication Equipment |
| SLIM | Service Level Improvement Method |
| SLIP | Serial Line Internet Protocol |
| SLLR | Single Line Loud Ringer |
| SLM | Signal Leakage Meter |
| SLM | Signal Line Measurement |
| SLM | Subscriber Loop Multiplex |
| SLOC | Small Local Open And Connected |
| SLOC | Small Local Open Connected |
| SLT | Signaling Link Termination |
| SLTS | Sri Lanka Telecom Services |
| SLV | Satellite Launch Vehicle |
| SMASE | Systems Management Application Service Element |