Artikel 19

1. [Notification of Common Office] If several States intending to become party to this Act have effected, or if several States party to this Act agree to effect, the unification of their domestic legislation on industrial designs, they may notify the Director General
(i) that a common Office shall be substituted for the national Office of each of them, and
(ii) that the whole of their respective territories to which the unified legislation applies shall be deemed to be a single Contracting Party for the purposes of the application of Articles 1, 3 to 18 and 31 of this Act.
2. [Time at Which Notification Is to Be Made] The notification referred to in paragraph (1) shall be made,
(i) in the case of States intending to become party to this Act, at the time of the deposit of the instruments referred to in Article 27(2);
(ii) in the case of States party to this Act, at any time after the unification of their domestic legislation has been effected.
3. [Date of Entry into Effect of the Notification] The notification referred to in paragraphs (1) and (2) shall take effect,
(i) in the case of States intending to become party to this Act, at the time such States become bound by this Act;
(ii) in the case of States party to this Act, three months after the date of the communication thereof by the Director General to the other Contracting Parties or at any later date indicated in the notification.