| Abbreviation | Definition |
|---|---|
| DIRC | Digital Information Resource Center |
| DIRD | Digital Integrated Receiver and Decoder |
| DIRF | Digital Information Research Foundation |
| DISA | Direct Inward Switch Access |
| DIW | Digital Information World |
| DL | Data Link |
| DL | DownLink |
| DLC | Digital Leased Circuit |
| DLC | Digital Line Controller |
| DLC | Digital Loop Carrier |
| DLE | Digital Line Equipment |
| DLI | Dialed Line Identification |
| DLIS | Directory Listing Inquiry System |
| DLOL | Digital Loss Of Link |
| DLR | Design Layout Record |
| DLR | Device Logic Ring |
| DLS | Dual Line Signalling |
| DLT | Double Leading Tone |
| DM | Delta Modulation |
| DMARC | DeMARCation point |