Sources originating outside the six domains; the text is not held. 6.2.1 names the external categories: other systems and devices that attackers can turn against the system, natural phenomena, and people with hostile intent, and 5.4 the ecosystem spill-overs such as attacks that use vulnerable IoT systems against other organizations and countries. Annex A's camera scenario (held in translation) lists sources of this kind: dependence on the electricity supply and on network services, cameras sited where weather and environmental conditions can affect them, and people intent on attacking or abusing systems over networks.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.