This standard specifies the coding methods and corresponding codes for my country's standard voltage levels, including the coding methods and codes for DC standard voltage and AC standard voltage with a standard frequency of 50Hz. This standard applies to the management of power generation, transmission, distribution, power consumption systems and electrical equipment, as well as information processing and information exchange. This standard does not apply to voltages representing signals, transmitted signals and measured values, nor to standard voltages for components, components or parts of equipment inside electrical installations.