For systems that do not use call-control roaming (typically VoIP over the internet on mobile, Wi-Fi or fixed access), the system must meet the requirements of 6.1 through 6.6 that apply towards its own client and the PSAP of the visited country when the client is abroad and makes an emergency communication.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.