Where installations cannot meet Part 2 they may use a specific Part 1 design (in Australia not for domestic installations) that meets Part 1 principles with no lesser safety; departures are acknowledged by the owner or operator, documented by a competent designer (why Part 2 was not used, how Part 1 is met, verification needed and done, owner requirements), kept on site, verified before service, and the switchboards concerned are permanently marked that part of the installation adopts a Part 1 solution.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.