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 unitsA closely related international standard on quantities and units is ISO 31.