Every core element is classified in one cell of a grid formed by the three layers and by the aspects of active structure, of behavior and of passive structure. The classification is indicative rather than rigid, so bridging elements such as business roles, or software that could sit in either the Application or Technology Layer, are allowed, and composite elements may combine aspects.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.