16 Article 24 The Headquarters of the Union 1. The Headquarters of the Union shall be in Addis Federal Democratic Republic of Ethiopia. Ababa in the 2. There may be established such other offices of the Union as the Assembly may, on the recommendation of the Executive Council, determine. Article 25 Working Languages The working languages of the Union and all its institutions shall be, if possible, African languages, Arabic, English, French and Portuguese. Article 26 Interpretation The Court shall be seized with matters of interpretation arising from the application or implementation of this Act. Pending its establishment, such matters shall be submitted to the Assembly of the Union, which shall decide by a two-thirds majority. Article 27 Signature, Ratification and Accession 1. This Act shall be open to signature, by the Member States of the OAU respective constitutional procedures. 2. The instruments of ratification Secretary-General of the OAU. 3. ratification and accession in accordance with their shall be deposited with the | Any Member State of the OAU acceding to this Act after its entry into force shall deposit the instrument of accession with the Chairman of the Commission.