Mandatory tests for LV installations: earthing system continuity (including PEN submain connection to main board earth), insulation resistance (1 megohm minimum with exceptions), polarity and correct circuit connections (combined in one clause by Amendment 2), fault-loop impedance on socket-outlet circuits that rely on automatic disconnection, and RCD operation; ELV parts are tested separately; failed tests and those they affect are repeated after rectification; results are recorded.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.