Telecommunications switching and transmission apparatus and teaching apparatus therefor; apparatus for the input, output, recording, transmission or reproduction of audio and video images; electronic apparatus for the input, output, processing, logging, sorting, transmission or reception of data; computers and microprocessors; office machines; encoding and decoding apparatus; magnetic data carriers; pre-recorded discs; software and encoding programs for computers or data processing apparatus; and parts and fittings for all the aforesaid goods