S/PDIF has also been designed to carry encoded multi-channel sounds, such as: AC-3, MPEG, DTS, etc. The channel-status bit contains information on whether or
not the receiving equipment should treat the stream as normal audio samples, or some other kind of data aforementioned.
S/PDIF can be passed along glass or plastic optical fiber, or along any single pair of wire, as it is unbalanced. Coaxial RCA connectors seem to be the most common connector on consumer electronics equipment, with the exception of Sony. Sony tends to make all of their digital interfaces optical.
S/PDIF has one major disadvantage. Being a consumer format, it supports copy protection schemes like SCMS (Serial Copy Management System). This protocol applies only to digital recordings, and prevents one digital copy of an original from being used to make more digital copies. Common mostly on DAT and MiniDisc recorders.
The other rival format of S/PDIF is AES/EBU, a balanced digital connector format.