| Subject | English | German |
| commun. | high level data link control | HDLC-Verfahren |
| commun. | High-level Data Link Control | Hochpegel-Datenübertragungssteuerung (bit-oriented synchronous PSDN protocol, ISO 3309 4335, DIN 66221) |
| comp., MS | High-level Data Link Control | High-Level Data Link Control (A protocol for information transfer adopted by the ISO. HDLC is a bit-oriented, synchronous protocol that applies to the data-link (message-packaging) layer (layer 2 of the ISO/OSI reference model) for computer-to-microcomputer communications) |
| comp. | high-level data-link control | Hochpegel-Datenleitungssteuerung |