Clause 8.1 sets out the concepts needed to identify a medicinal product uniquely and to associate it with PhPIDs. The public contents name the medicinal product identifier and the package component identifier as the regional identifiers, and the pharmaceutical product identifier as the composition-level identifier. The clause is about the association between them: one medicinal product can be associated with several PhPIDs, because a product can be presented in several strengths or forms, and one PhPID can be associated with several medicinal products, because the same composition can be authorised in several regions. The exact association rules and cardinalities are not in the public preview and are not stated in the text we hold. What the structure shows is that the model expects a many-to-many relationship, not a single foreign key.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.