The purpose of this standard is to establish the type of linear or two-dimensional bar code to be used in the marking of metering equipment and its accessories, as well as the characteristics to be encoded and the format and size of the information code. The indications contained in this standard shall be applicable to metering equipment, associated devices and accessories to be installed in Spain for the measurement of electrical energy supplied or generated at supply points of the electrical network. Specifically, they must be applicable to: - directly connected and indirectly connected electricity meters; - seals for meters and electrical metering equipment; - metering transformers for billing customers in low and medium voltage (voltage less than or equal to 33 kV) or for internal control uses of the distribution network; - modems and routers for electric energy telemetering; - data concentrators for smart metering; - PLC signal filters for smart metering. - data concentrators for advanced monitoring - digitizer cards for advanced monitoring - low voltage output meters for advanced supervision - neutral voltage watchdog for advanced supervision - PLC gateways, gateways and PLC base nodes