Kola comments on the finds on p.57-9 of his report:
Particularly interesting is a set of 304 pieces of concrete rings with the diameter of about 6 cm and 1 cm thickness on which 5 number figures had been pressed (inventory number 233198). They were excavated at the area of a stone floor in the western part of the central room in big concentration (site 11 e/98 ). In upper part of these rings small holes were stated, which probably served to hang them up. Their destination[sic] is unknown (fig. 115-117).
Kola makes no further attempt to interpret the use of these objects.
The numbered plates looks like this:



So here we have 304 small round plates with an individual 5-digit number on each of them and a small hole in the upper part. As Kola writes, the holes could serve the purpose of hanging them up, but what would be the purpose of hanging up numbered plates like that. Could it have to do with some kind of work organizing?
Of course, the holes could also have a piece of string out through it, enabling for someone to carry the plate around the neck for instance.
Wouldn't, by the way, the individual five digit numbers suggest that there existed a lot more numbered plates than the 304 found by Kola at Building D, possibly several thousands?
Could one possibly interpret those plates as something the arrivals were given at handing over their clothes and personal belongings (so that they would be able to retrieve all or some of their belongings afterwards) before being gassed, if we are to believe the exterminationists, or being showered and desinfected, if we are to believe the revisionists. The hole in the plates together with a spring would then enable the "victims" to carry the object around their necks while naked and taking a shower. This interpretation of course seems less likely in the gassings scenario, since it would mean that the plates would have to been retrieved from thousands of bodies after the gassing - something which would delay the gassing and interring process.
Has anyone seen any similar looking numbered concrete plates by the way?