A documented complaints procedure describes how complaints are received, substantiated, investigated and decided, how they are tracked and recorded with the actions taken, and how appropriate action is ensured; a description of the process is publicly available. On receipt the provider confirms that the complaint concerns PT activities and, if it does, resolves it, gathering all the information needed to decide whether it is substantiated; where possible it acknowledges receipt and gives the complainant the outcome and progress reports, and formally notifies the complainant when handling has ended. Investigation and resolution involve no discriminatory action; resolution is made, or else reviewed and approved, by people with no involvement in the matter, or by an alternative that does not compromise impartiality where resources do not permit; and the provider is responsible for all decisions at every level of the process.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.