Wherever a device or system able to contaminate drinking (potable) water is joined, whether directly or by an indirect route, to any section of a water service, it must be protected against backflow by a registered testable device carrying a high hazard rating that guards against back-pressure as well as back-siphonage, as AS/NZS 3500.1 requires. The guideline notes this covers any water supplied to the facility, for example sinks, basins and the supply to an autoclave.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.