Historical
BS ISO 11532:2012
Aircraft ground equipment. Graphical symbols (British Standard)
ISO 11532:2012 establishes common graphical symbols for use on all types of aircraft ground support equipment. They have been compiled for the benefit of those who deal with such equipment, such as airlines, airport handling agencies, airport authorities, manufacturers, etc., in order to facilitate fast and accurate identification of controls, indicators and decals of powered and unpowered equipment.
British Standards Institution [bsi]