An arrangement for the control of viewing of a television programme in which a classification code is transmitted with the video signal, for example in an extension packet of a teletext signal, includes a decoder (23) which detects the received codes and passes them to a microcontroller (27). An authorised user is able to enter codes of permitted programme classifications by means of a remote control unit (28). Codes representing these permitted classifications are stored in a non-volatile memory (29). The received and permitted codes are compared in the micro controller (27) that inhibits the video (25) and/or audio (32) circuits if the received codes are not permitted codes. A second tuner 40 is provided which is controlled by the processor (27) to cycle through the available channels and for each channel the processor determines the classification codes being transmitted and notes those channels which have non-permitted (or permitted) classification codes. When requests for channel changes are made the processor (27) determines whether the channel has a permitted classification code and if not causes the tuner (21) to select an alternative channel.