This part of the 81355 International Standard, published jointly by IEC and ISO, provides rules and guidelines for the classification and designation of information based on its inherent content. This document is applicable for information used in the life cycle of a system, e.g., industrial plants, construction entities and equipment. This document defines classes of information and their codes (Information Class Code ICC). The defined classes and codes provided are intended to be used as values associated with metadata, e.g., in information management systems (see IEC 82045-1 and IEC 82045-2). The rules, guidelines and classes are general and are applicable to all technical areas, for example mechanical engineering, electrical engineering, construction engineering and process engineering. They can be used for systems based on different technologies or for systems combining several technologies. This document is also a horizontal publication intended for use by technical committees in preparation of publications related to classification and designation of information in accordance with the principles laid down in IEC Guide 108.