Before anyone works on or near exposed conductors or parts that have been de-energized, a competent person must first have: positively identified the equipment and conductors, every energy source and the isolation points; isolated them from all energy sources; secured the isolation; discharged stored energy where needed (for example capacitors); proven de-energization of all relevant equipment and conductors; identified the limits of the safe work area; and displayed warning notices. All conductors, neutral and earth included, are treated as live until proven otherwise. For complex installations (backup and generator supplies, multiple or remote isolation points, safety services) a second competent person should check the isolation procedure. The equipment to be worked on, the isolation points and all energy sources, non-electrical ones included, must be positively identified (for example by line diagrams, labels and ID numbers).
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.