This Recommendation defines the mapping rules for the carriage of an AES/EBU bit stream as defined in Recommendation ITU-R BS.647 over horizontal ancillary data space of serial digital interfaces conforming to Recommendation ITU-R BS.656 and ITU-R BT.799. The data carried in the bit stream may be two channels of periodically sampled and linearly represented digital audio data, or other data formatted to fit the payload space of the AES/EBU bit stream.