Letter symbols to be used in electrical technology - Part 2: Telecommunications and electronics (IEC 60027-2:2005); German version EN 60027-2:2007— 92 стр.
Industrial systems, installations and equipment and industrial products - Designation of signals - Part 1: Basic rules (IEC 61175-1:2015); German version EN 61175-1:2015— 53 стр.