Clause 7.1 introduces the strata and levels used to identify a pharmaceutical product. The published edition works with two strata: the substance stratum and the specified substance stratum. Within each stratum the model builds four levels. The first level is the substance or substances. The second adds strength and reference strength. The third adds the administrable dose form. The fourth adds strength and dose form together. The specified substance stratum does the same with the specified substance, which is the salt, hydrate or other form that matters for the product. The public contents name 7.1.2 as the specified substance level and 7.1.3 as the identification of the specified substance stratum. The detailed rules for assigning a level are not in the text we hold. The public FDA material describes the same four-level construction and calls the identifiers PhPIDs.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.