A radio frequency receiver for receiving supplementary data transmitted with a radio station signal, said supplementary data comprising one or more information word fields containing supplementary data transmitted with the radio station signal, said receiver comprising: a host processor for processing said supplementary data; a supplementary data demodulator and decoder for demodulating and decoding a received radio signal to generate a stream of bits representing one or more information word fields; a information word type memory for storing one or more information word type fields; detection circuitry arranged to receive and compare the information word type field decoded by the supplementary data decoder with one or more information word type fields stored in the information word type memory, and to provide a matched condition signal in response to a match between one or more decoded information word type fields and one or more of said corresponding stored information word types fields, and wherein the receiver is arranged to, in response to the matched condition signal, cause the corresponding supplementary data to be processed by means of the host processor.