| Abbreviation | Definition |
|---|---|
| CYTG | Coole Youtuber Gang |
| D/A | Digital-to-Analog converter |
| D/I | Drop and Insert |
| D3 | Digital channel bank, Third generation |
| D4 | Digital channel bank, Fourth generation |
| DAC | Digital-to-Analog Converter |
| DACS | Digital Access Carrier System |
| DACS | Digital Access Cross-Connect |
| DAHDI | Digium/Asterisk Hardware Device Interface |
| DAL | Dedicated Access Line |
| DAMPS | Digital Advanced Mobile Phone System |
| DAS | Distributed Antenna System |
| DAVIC | Digital Audio VIdeo Council |
| dB | Decibel |
| DB | Dial Back |
| DB | Dropped Burst |
| DBMS | DataBase Management System |
| DBN | Dial-Back Number |
| DBoRs | Data Base of Records |
| dBRN | deciBel Relative to Noise |