Revidert
IEC 60598-2-20:1982/AMD2:1992 ED1
IEC 60598-2-20:1982/AMD1:1987 ED1
IEC 60598-2-20:1982 ED1
IEC 60598-2-20:1996+AMD1:1998 CSV
IEC 60598-2-20:2010 ED3