A source may propose and accept permanent, quantifiable limits enforceable as a practical matter (compliance readily determinable from records and reports) to avoid Class I status or other requirements, showing they are at least as stringent as what they replace and do not relax any implementation plan or federally enforceable requirement; such Class II permits go to EPA for review during comment.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.