Clause 7.5 describes the elements of the substance stratum, PhPID_SUB_Lx. The public contents name five subclauses: the construct of the stratum, the substance set, the administrable dose form, the unit of presentation and the medical device. Read as a set, they say that the identifier at this stratum is not built from a substance name alone. It needs the set of substances that together make the product, the form in which the product is administered, the unit in which the presentation is counted, and any device that is part of the product. The construct subclause is the assembly rule. The detailed element definitions and the assembly order are not in the public preview and are not stated in the text we hold. The public FDA material confirms that substance, dose form and strength are the ingredients of the identifier and that the dose form has to come from a controlled terminology.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.