Sovereign competence theory of opposability to subdivisions
As Klabbers suggested, one often cited justification for the opposability of international norms to non-State actors is the competence of the State to enter into international legal commitments as the representative of those non-State actors.
An example that supports this theory of opposability is the opposition of a treaty to which a State is party to individuals who are organs of such a State or under its sovereign jurisdiction (312) observed in the practice of international criminal law, particularly the International Criminal Court (ICC).
Because of this, the ICC example supports the opposability of parent States' BITs to their subdivisions.
Third is the opposability of a BIT to a subdivision which (typically) is not a party thereto.
This is the theory of opposability developed supra.
As regards the publicity and opposability to third parties of the deed of transfer for the patrimony by appropriation, it is required to make a registration with the trade registry, to register it with the land book whenever the goods of the patrimony by appropriation include real estate, movable securities and/or other rights, deeds or legal relations related to the real estate properties registered with the land book and the registration with the electronic archive of movable securities, given that the assignment of a universality of receivables is involved (art 1579 of the Civil Code).
Also, related to the opposability of receivable assignment to debtors, it is required to send the deed of transfer to all the assignor's debtors (52) (art.
2003) (explaining that in the absence of a general practice, customary law becomes "a network of special relations based on opposability, acquiescence, and historic title"); ANTONIO CASSESE, INTERNATIONAL LAW IN A DIVIDED WORLD 346-347 (1986); Lowe, supra note 7, at 209-11; Donald W.
Weiler eds., 1988) ("There are cases where a custom is itself the object of dispute, where its applicability is directly at issue, where the parties do not agree as to the opposability of the rule.