IEC 60664-3:2016(E) is available as IEC 60664-3:2016 RLV which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition.

IEC 60664-3:2016 applies to assemblies protected against pollution by the use of coating, potting or moulding, thus allowing a reduction of clearance and creepage distances as described in IEC 60664-1. This document describes the requirements and test procedures for two methods of protection:
- type 1 protection improves the microenvironment of the parts under the protection,
- type 2 protection is considered to be similar to solid insulation. This edition includes the following significant technical changes with respect to the previous edition:
a) information added concerning interpolation,
b) provided scratch test is only for type 2 protection,
c) renumbered the scratch test to follow the visual examination test, since it makes more sense there,
d) separated the tables under what is now called Annex A, to make them clearer.