IEC 60027 (formerly IEC 27) is the International Electrotechnical Commission's standard on Letter symbols to be used in electrical technology. It consists of several parts:
IEC 60027-1: General
IEC 60027-2: Telecommunications and electronics
IEC 60027-3: Logarithmic and related quantities, and their units
IEC 60027-4: Symbols for quantities to be used for rotating electrical machines
IEC 60027-6: Control technology
IEC 60027-7: Physiological quantities and units
IEC 60027: Polyvinyl chloride insulated cables of rated voltages up to and including 450∕750V