Proposed definition of the scope of a UI in terms of product compliance with the regulations under which it has been approved. If a product modification would require its testing for conformity with one or more UN Regulations as a new approval, then the UI must be changed to distinguish the product from similar product(s) approved previously. If a modification to a product has no consequences in terms of its current conformity, compliance, certification or approval(s), then the product may continue to use the current UI assigned pursuant to its approval.