xsettings and 64 bit machines

[Scott Violet <Scott Violet sun com>]

The spec for xsettings, at
http://www.freedesktop.org/standards/xsettings/xsettings.html
mentions X defines in a number of places (such as CARD32 and CARD16)
along with a byte count. For example, the header is listed as:

1      CARD8    byte-order
3               unused
4      CARD32   SERIAL
4      CARD32   N_SETTINGS

On 64 bit machines CARD32 appears to be 8 bytes in length. So, which
column dictates the actual number of bytes? The byte column or the
number of byes of the underlying type? For example, on a 64 machine
will SERIAL be 4 bytes or 8 bytes?
Thanks,

      -Scott Violet (scott violet sun com)