This part of IEC 61850@ which is a Technical Specification@ applies to power utility automation systems (PUAS). It defines the communication between intelligent electronic devices (IEDs) in the power utility automation system and the related system requirements. This document contains the glossary of specific terminology and definitions used in the context of Power Utility Automation Systems within the various parts of the standard. This document is@ by its nature@ a living part since new definitions and abbreviations will be created continuously in the standard documents that are being written inside the IEC related to IEC 61850.