IEC 60626-1:2023 is available as IEC 60626-1:2023 RLV which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition.

IEC 60626-1:2023 contains the definitions related to and the general requirements to be fulfilled by combined flexible materials for electrical insulation. This document does not include mica papers used as a primary component, which are covered by the IEC 60371 series, but insulation materials based on mica paper can be used as component of a combined flexible material. Materials which conform to this specification meet established levels of performance. However, the selection of material by a user for a specific application is based on the actual requirements necessary for adequate performance in that application and not based on this specification alone. This fourth edition cancels and replaces the third edition published in 2009. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
a) the materials available for use within this series of standards have been updated;
b) a framework has been created to allow test methods beyond those used for quality control specifications to allow for testing for qualification purposes.