Rack models each cabinet unit by unit, down to every patch panel port and switch port, its patch cable and its VLAN.

Rack diagrams in spreadsheets rarely show the patching, and after a few moves the labels no longer match. Finding a free port or the device behind a port means standing at the cabinet.
The connection panel in the cabinet where the cables from the wall outlets arrive.
The port on the network switch that feeds the device through the patch panel and outlet.
Yes. Add the devices unit by unit and patch them; the record becomes the as-built once installed.
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