Artikel 27

1. If a State has two or more territorial units in which different systems of the law are applicable in relation to matters dealt with in this Convention, it may at the time of signature, ratification, acceptance, approval or accession declare that this Convention shall extend to all of its territorial units or only to one or more of them and may alter this declaration by submitting another declaration at any time.
2. Any such declaration shall be notified to the depositary and shall state expressly the territorial units to which the Convention applies.
3. If a State makes no declaration under this Article, the Convention is to extend to all territorial units of that State.