of International Child Abduction, as between Parties to both Conventions. Nothing, however, precludes provisions of this Convention from being invoked for the purposes of obtaining the return of a child who has been wrongfully removed or retained or of organising access rights.Article 51In relations between the Contracting States, this Convention replaces the Convention of 5 October 1961 concerning the powers of authorities and the law applicable in respect of the protection of minors, and the Convention governing the guardianship of minors, signed at The Hague 12 June 1902, without prejudice to the recognition of measures taken under the Convention of 5 October 1961 mentioned above.Article 521. This Convention does not affect any international instrument to which Contracting States are Parties and which contains provisions on matters governed by the Convention, unless a contrary declaration is made by the States, Parties to such instrument.2. This Convention does not affect the possibility for one or more Contracting States to conclude agreements which contain, in respect of children habitually resident in any of the States, Parties to such agreements, provisions on matters governed by this Convention.3. Agreements to be concluded by one or more Contracting States on matters within the scope of this Convention do not affect, in the relationship of such States with other Contracting States, the application of the provisions of this Convention.4. The preceding paragraphs also apply to uniform laws based on special ties of a regional or other nature between the States concerned.Article 531. The Convention shall apply to measures only if they are taken in a State after the Convention has entered into force for that State.2. The Convention shall apply to the recognition and enforcement of measures taken after its entry into force as between the State where the measures have been taken and the requested State.Article 541. Any communication sent to the Central Authority or to another authority of a Contracting State shall be in the original language, and shall be accompanied by a translation into the official language or one of the official languages of the other State or, where that is not feasible, a translation into French or English.2. However, a Contracting State may, by making a reservation in accordance with Article 60, object to the use of either French or English, but not both.Article 551. A Contracting State may, in accordance with Article 60:(a) reserve the jurisdiction of its authorities to take measures directed to the protection of property of a child situated on its territory;(b) reserve the right not to recognise any parental responsibility or measure in so far as it is incompatible with any measure taken by its authorities in relation to that property.2. The reservation may be restricted to certain categories of property.Article 56The Secretary General of The Hague Conference on Private International Law shall at regular intervals convoke a Special Commission in order to review the practical operation of the Convention.CHAPTER VIIFINAL CLAUSESArticle 571. The Convention shall be open for signature by the States which were Members of The Hague Conference on Private International Law at the time of its eighteenth session.2. It shall be ratified, accepted or approved and the instruments of ratification, acceptance or approval shall be deposited with the Ministry of Foreign Affairs of the Kingdom of the Netherlands, depositary of the Convention.Article 581. Any other State may accede to the Convention after it has entered into force in accordance with Article 61, paragraph 1.2. The instrument of accession shall be deposited with the depositary.3. Such accession shall have effect only as regards the relations between the acceding State and those Contracting States which have not raised an objection to its accession in the six months after the receipt of the notification referred to in Article 63(b). Such an objection may also be raised by States at the time when they ratify, accept or approve the Convention after an accession. Any such objection shall be notified to the depositary.Article 591. If a State has two or more territorial units in which different systems of 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 the Convention shall extend to all its territorial units or only to one or more of them and may modify 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.Article 601. Any State may, not later than the time of ratification, acceptance, approval or accession, or at the time of making a declaration in terms of Article 59, make one or both of the reservations provided for in Article 54(2), and Article 55. No other reservation shall be permitted.2. Any State may at any time withdraw a reservation it has made. The withdrawal shall be notified to the depositary.3. The reservation shall cease to have effect on the first day of the third calendar month after the notification referred to in the preceding