spdif really only carries 20 bits of audio?

[poodlebuild]

Roger Nichols in EQ:

"Also, keep in mind that AES can contain 24 bit audio, but S/PDIF can only contain 20 bit audio because the extra bits are used for the copy protection and sample rate flags."

From Wikipedia:

"S/PDIF is meant to be used for transmitting 20 bit audio data streams plus other related information. To transmit sources with less than 20 bits of sample accuracy, the superfluous bits will be set to zero. S/PDIF can also transport 24 bit samples by way of four extra bits, but not all equipment supports this, and might ignore these extra bits."

What about the 001 and 002?