Generation systems (generators, stand-alone systems, grid inverters, batteries) supplementing the installation are selected per their standards, controlled and isolated (no inverter downstream of a generator changeover unless backfeed is prevented; isolation details may vary per other standards), protected against overcurrent, earthed, and connected so an alternative supply does not switch the incoming neutral at an MEN board, with the MEN connection within the installation.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.