Should shared be removed from system.memory.state values?

I'm reviewing the usage naming convention:

Where appropriate, the sum of usage over all attribute values SHOULD be equal to the limit.

and at least on my system, the shared dimensions appears to be double counted:

root@972900a4c455:/# free
               total        used        free      shared  buff/cache   available
Mem:        32847132     2214804    30020716       80216      611612    30172244

doing the math:

32847132 = 2214804 + 30020716 + 611612

cc @open-telemetry/semconv-system-approvers