1970DIN EN 60027-2 E:2014-05 Letter symbols to be used in electrical technology - Part 2: Telecommunications and electronics
2009DIN EN 80000-13:2009 Quantities and units - Part 13: Information science and technology (IEC 80000-13:2008); German version EN 80000-13:2008
2007DIN EN 60027-2:2007 Letter symbols to be used in electrical technology - Part 2: Telecommunications and electronics (IEC 60027-2:2005); German version EN 60027-2:2007
0000 DIN IEC 60027-2:2003
1992DIN 1304-6:1992 Letter symbols for physical quantities; symbols to be used in electrical communication technology