I'm unsure of what DNM means on this schematic
The parts labeled DNM most likely means &quot;Do Not Mount&quot;.
The parts are drawn in the schematics and on the PCB board, but the components are not placed on the board during manufacture.
They are left out if not needed for a certain board revision, but if later changes need to be made, it means that existing boards can still be used after updating the Bill Of Materials.
For example if the RTC crystal changes for some reason, then the capacitors can be placed there if necessary.