1. If several countries of the Special Union agree to effect the unification of their domestic legislation’s on marks, they may notify the Director General:
(a) that a common Office shall be substituted for the national Office of each of them, and
(b) that the whole of their respective territories shall be deemed to be a single country for the purposes of the application of all or part of the provisions preceding this Article.
2. Such notification shall not take effect until six months after the date of the communication thereof by the Director General to the other contracting countries.