Applies to electrical equipment using signals in the frequency range 3 kHz to 148,5 kHz to transmit information on low voltage electrical systems, either on the public supply system or within installations in consumers' premises. Does not specify the signal modulation methods nor the coding methods nor functional features (except those for the prevention of mutual interference). Environmental requirements and tests are excluded. Covers definitions, frequency bank, access protocol, transmitter output voltage, disturbance limits, test conditions and inadvertent operation.