For a manifestly unfounded or excessive request (for example one merely repeating earlier requests) the controller may charge a reasonable fee or refuse, bearing the burden of showing the request is so; if it refuses it must tell the data subject its reasons and the right to complain to the Commissioner without undue delay and within the applicable time period. Regulations may cap fees and require published fee guidance.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.