The CCIR considering a) that the definition of synchronizing reference signals for component digital studios would be of benefit in the implementation of equipment operating in accordance with Recommendations 601 and 656; b) that such signals should have a maximum of commonality between the 525 line and 625 line versions; c) that signals in accordance with Recommendation 656 contain in a conveniently accessible and accurate form all the information required to synchronize digital component equipment; d) that the use of digital circuitry introduces the possibility of new techniques in studio synchronization; e) that equipment in accordance with Recommendations 601 and 656 may have to operate in a mixed analogue and digital environment for a considerable period; f) that compatibility with synchronizing reference signals for component analogue studios would be an advantage; g) that signals generated in accordance with Recommendation 470 are widely used for synchronization in studios.