Where PID is used only internally and is never disclosed to the public or to third parties, consent may also be obtained by email with additional assurance that the sender is the parent: a delayed confirmatory email after consent, or the parent supplying a postal address or phone number, followed by confirmation by letter or phone, the confirmation repeating all the information of the earlier notice and explaining how to revoke the consent.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.