Article 28

(1)
(a) Any country of the Union which has signed this Act may ratify it, and, if it has not signed it, may accede to it. Instruments of ratification or accession shall be deposited with the Director General.
(b) Any country of the Union may declare in its instrument of ratification or accession that its ratification or accession shall not apply to Articles 1 to 21 and the Appendix, provided that, if such country has previously made a declaration under Article VI (1) of the Appendix, then it may declare in the said instrument only that its ratification or accession shall not apply to Articles 1 to 20.
(c) Any country of the Union which, in accordance with subparagraph (b) , has excluded provisions therein referred to from the effects of its ratification or accession may at any later time declare that it extends the effects of its ratification or accession to those provisions. Such declaration shall be deposited with the Director General.

(2)
(a) Articles 1 to 21 and the Appendix shall enter into force three months after both of the following two conditions are fulfilled:
(i) at least five countries of the Union have ratified or acceded to this Act without making a declaration under paragraph (1)(b),
(ii) France, Spain, the United Kingdom of Great Britain and Northern Ireland, and the United States of America, have become bound by the Universal Copyright Convention as revised at Paris on July 24, 1971.
(b) The entry into force referred to in subparagraph (a) shall apply to those countries of the Union which, at least three months before the said entry into force, have deposited instruments of ratification or accession not containing a declaration under paragraph (1) (b).
(c) With respect to any country of the Union not covered by subparagraph (b) and which ratifies or accedes to this Act without making a declaration under paragraph (1) (b), Articles 1 to 21 and the Appendix shall enter into force three months after the date on which the Director General has notified the deposit of the relevant instrument of ratification or accession, unless a subsequent date has been indicated in the instrument deposited. In the latter case, Articles 1 to 21 and the Appendix shall enter into force with respect to that country on the date thus indicated.
(d) The provisions of subparagraphs (a) to (c) do not affect the application of Article VI of the Appendix.

(3) With respect to any country of the Union which ratifies or accedes to this Act with or without a declaration made under paragraph (1) (b), Articles 22 to 38 shall enter into force three months after the date on which the Director General has notified the deposit of the relevant instrument of ratification or accession, unless a subsequent date has been indicated in the instrument deposited. In the latter case, Articles 22 to 38 shall enter into force with respect to that country on the date thus indicated.