9 apparatus for digital recording, transmission and reproduction of sound and images, namely, digital mixing desks for TV and radio studios, digital radios and audio cassette recorders, video cassette recorders, digital audio recorders, digital audio players, digital video recorders and digital video players, digital home theater systems comprising audio decoders, video decoders, audio amplifiers, television screen/displays and speakers, set-top-boxes, and digital data compressors/decompressors sold as a unit; blank magnetic data carriers and blank magnetic data recording carriers; blank optical data carriers and blank optical data recording carriers; and blank mechanical data carriers and blank mechanical data recording carriers