Patients contacting a service at night need its practical facts quickly. The service makes current information available, by phone message, website and printed material, covering at least its contact details, the hours it operates and the area it covers, the practitioners who work for it, its billing principles, how patients can give feedback or raise a complaint, and how it manages personal health information. The information is kept accurate as arrangements change.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.