This standard provides guidance for the definition of concepts that are used to describe classes and properties in a change request, submitted for update of the content of IEC Common Data Dictionary (IEC CDD). This includes - a basic understanding of key concepts and procedures used within IEC CDD; - a binding reference for quality control of IEC 61360 compliant dictionary content; - guidance on documents where necessary in-depth knowledge can be acquired (see clauses 2 and 12). This standard includes the following subjects: - basic overview about fundamental concepts of IEC 61360; - formulating definitions and other textual elements; - overview of IEC maintenance procedure for IEC CDD; - checklist for providing input to the dictionary content.