Industrial systems, installations and equipment and industrial products - Structuring principles and reference designations - Part 2: Classification of objects and codes for classes
IEC 81346-2:2026 establishes classification schemes with defined object classes and their associated letter codes. The codes are primarily intended for use in reference designations and for designation of generic types.
The classification schemes are applicable for objects in all technical disciplines and all branches of industry.
IEC 81346-2:2026 has the status of a horizontal standard in accordance with IEC Guide 108. It is also intended for use by technical committees in preparation of publications related to reference designations in accordance with the principles laid down in IEC Guide 108.
IEC 81346-2:2026 cancels and replaces the second edition published in 2019. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous edition:
a) existing class definitions have been reviewed and further clarified;
b) Table 2 in this document has been updated to include the information from Table 3 in the previous edition;
c) Table 2 in this document has been further updated with the addition of new classes, modification of class names, and identification of obsolete classes;
d) Table 4 in the previous edition is moved to become Table 5 in this document and has been updated with the addition of new classes, modification of class names, and identification of obsolete classes;
e) additional examples have been added to several classes;
f)new classification schemes for construction complexes and construction entities have been added as Table 3 and Table 4, respectively, intended to replace the classification tables in ISO 81346-10:2022, Annex C;
g) the former Clause 7 "Classification of objects applicable for infrastructure" and the former Annex C "Object classes related to objects in a generic infrastructure" have been deleted following the publication of ISO 81346-10, ISO 81346-12 and IEC 81346-14;
h) the former Annex D "Comparison between Tables 1, 2 and 3 of IEC 81346-2:2019 and Tables 1 and 2 of IEC 81346-2:2009" has been deleted as this document is a revision of IEC 81346-2:2019 and therefore not necessary to maintain.
