References to international standards are in a brief form. The full references are below:
IEC TR 60878:2015 (ed. 3.0), Graphical symbols for electrical equipment in medical practice
IEC 60417:2002 DB, Graphical symbols for use on equipment
ISO 7010:2011, Graphical symbols – Safety colours and safety signs – Registered safety signs.
ISO 7000:2014 (ed. 5.0), Graphical symbols for use on equipment -- Registered symbols
EN 50419:2006, Marking of electrical and electronic equipment in accordance with Article 11(2) of Directive 2002/96/EC (WEEE)