I scanned through the HYCON manual for the 12P65, and there is no clear explanation, how the digital representation of the A/D is calculated.. anyhow, the output seems to be much more than +/- 5000d, as the polarity, gain selection, Chopper (i.e. Offset) and filter parameters also influence that output data..
As far as I understood, it's up to 3FFFF, this way.
So it's well possible, to have any random resolution in the range of 5000d, which should be the useful magnitude of resolution, and is also related to the usual 5xxx ranges of such DMMs.. all examples are done on that full scale value.
Concerning the special Bryman marking, that might simply be related to the firmware, as it's most cost effective, that the chip manufacturer already flashes the software during final IC test.
Frank