IEC 81346

• Part 1: Basic rules (IEC 81346-1:2022) ^[3]
• Part 2: Classification of objects and codes for classes (IEC 81346-2:2019) ^[4][5]
• Part 10: Power supply systems (ISO 81346-10:2022) ^[6][7]
• Part 12: Construction works (ISO 81346-12:2018) ^[8]
• Part 14: Manufacturing and Processing Systems (IEC 81346-14) ^[9]
• Part 8: Properties
• Part 20: Vehicle Systems
• Part 50: Processes

Future developments of the standards on reference designations will be made in cooperation between the IEC and the ISO and published as IEC 81346. (Standards developed in cooperation between IEC and ISO are assigned numbers in the 80000 series)

The standard consists of two parts and two supplements:

• EN 81346-1: General rules (IEC 81346-1:2022)
• EN 81346-2: Classification of objects and coding of classes (IEC 81346-2:2019)

The supplementary sheets for application guidelines (IEC/TR 61346-3:2001) and considerations of terms and their relationships (IEC 61346-4:1998) for DIN EN 61346 were withdrawn in May 2010 without replacement.

They are translations of the International Standard IEC 81346 published by the IEC. In 1997 the IEC changed the numbering of the IEC publications and added 60000 to the standard numbers used up to 1997. For example, IEC 61346 from 1996 was published under the number IEC 1346 but was listed under IEC 61346.

From 2010, the standards for reference marking will be published as a joint IEC/ ISO standard in the 80000 number range and then published under the number 81346.

Preceding standard IEC 61346:1996 has been withdrawn and is replaced by ISO/IEC 81346.

ISO 81346-12, also known as RDS-CW (Reference Designation System for Construction Works), is the industry-specific application of the ISO/IEC 81346 standard series developed for the construction sector. It provides structuring principles and reference designation methodologies tailored to construction projects, facilitating classification and identification within the building and infrastructure environments, as well as utility and HVAC.^[10]

RDS-CW is designed to integrate with broader classification and structuring systems (such as BIM^[11][12]) enabling consistent designation of construction elements and the potential for alignment with other ISO/IEC 81346 applications like power system designations.

ISO 81346-10, commonly referred to as RDS-PS (Reference Designation System for Power Supply Systems) ^[13] is the part of the ISO/IEC 81346 standard series that defines reference designations, principles, and structuring rules specifically for power and energy systems. ^[10] Unlike RDS-PP (Reference Designation System for Power Plants), the current ISO/IEC 81346-10:2022 edition is published as a full international standard, reflecting broader applicability and alignment with the core structuring principles of the 81346 series.^[14]

RDS-PS supports clear and consistent designation of systems and system elements within every power and energy domain and industry, serving industries such as electrical power generation, transmission, and distribution, as well as other sectors where power supply structures are fundamental. ^[10]

In support of ISO/IEC 81346-10:2022, the supplementary document ISO/TS 81346-101:2025, “Modelling concepts, guidelines and requirements for power supply systems”, has been published as a Technical Specification (TS). It provides additional modelling principles and practical guidance for the application of 81346-10 within power supply systems. ^[15]

IEC 81346-14, referred to as RDS-MS (Reference Designation System for Manufacturing and Processing Systems), ^[9] is a part of the ISO/IEC 81346 series currently under development for systems within the manufacturing and processing sector.

It provides industry-specific classification libraries intended for application across manufacturing and process industries, including consumer goods, machine building, industrial equipment, food and beverage, pharmaceuticals, packaging, and mining.^[10]

Currently, it is in the Final Draft International Standard (FDIS) stage of development, and once published, RDS-MS will offer a harmonized approach to structuring and identifying systems and components across manufacturing industries and process-oriented environments.^[9]

• Part 8: 81346-8: Properties ^[16]

ISO/IEC 81346-8 defines principles and rules for the designation and identification of properties associated with objects and systems. The standard supports the consistent specification of characteristics in technical documentation and is intended to strengthen the relationship between objects and their properties, particularly during the design and engineering phases.^[10]

• Part 20: 81346-20: Vehicle Systems ^[17]

ISO/IEC 81346-20, also known as RDS-VE (Reference Designation System for Vehicles), defines the principles and rules for structuring systems within vehicles and assigning reference designations. The standard addresses vehicles in a broad sense and is intended to support the design, planning, production, operation, and maintenance of aircraft, vessels, motor vehicles, rail vehicles, and other means of transportation.^[10]

• Part 50: 81346-50: Processes ^[18]

ISO/IEC 81346-50 establishes principles and rules for the structuring and designation of processes and activities, rather than physical systems. It introduces a standardized framework for modelling and assigning reference designations to actions and operational activities, supporting consistent identification across IT systems, documentation, and technical information management.^[10]

RDS4X website is a non-profit group set up to support collaboration among stakeholders working with the implementation of ISO/IEC 81346.

• Reference designator
• Functional specification
• List of IEC standards