Clause 5.1 is the requirement that turns the vocabulary into a field list. It addresses the elements needed to identify a pharmaceutical product uniquely. The public contents place it first in the requirements clause, ahead of the exchange requirement, which reflects the order of the problem: decide what identifies the product, then decide how the identification travels. The elements are drawn from the companion standards: the substance or substances, the specified substance where the salt or hydrate form matters, the strength and its unit, the administrable dose form, the unit of presentation and the medical device where one is part of the product. The clause does not invent a new element set; it says which of the existing IDMP elements are needed for this identifier and how they combine. The exact normative wording is not in the public preview, so the mandatory or optional status of each element is not stated in the text we hold.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.