Rule 27 - Records of Cases A special record, with a reference number and initialed, in which shall be entered the date of registration of each petition and communication and that of the closure of the procedure relating to them before the Commission, shall be kept at the Secretariat. Chapter VI - Subsidiary Bodies Rule 28 - Establishment of Committees and Working Groups 1. The Commission may during a session, taking into account the provisions of the Charter establish, if it deems it necessary for the exercise of its functions, committees or working groups, composed of the members of the Commission and send them any agenda item for consideration and report. 2. These committees or working groups may, in consultation with the Secretary General, be authorised to sit when the Commission is not in session. 3. The members of the committees or working groups shall be appointed by the Chairman subject to the approval of the absolute majority of the other members of the Commission. Rule 29 - Establishment of Sub-Commissions 1. The Commission may establish Sub-Commissions of experts after the prior approval of the Assembly. 2. Unless the Assembly decides otherwise, the Commission shall determine the functions and composition of each Sub-Commission. Rule 30 - Offices of the Subsidiary Bodies Unless the Commission decides otherwise, the subsidiary bodies of the Commission shall elect their own officers. Rule 31 - Rules of Procedure The Rules of Procedure of the Commission shall apply, as far as possible to the proceedings of its subsidiary bodies. Chapter VII - Public Sessions and Private Sessions Rule 32 - General Principle The sittings of the Commission and of its subsidiary bodies shall be held in public unless the Commission decides otherwise or it appears from the relevant provisions of the Charter that the meeting shall be held in private. Rule 33 - Publication of Proceedings At the end of each private or public sitting, the Commission or its subsidiary bodies may issue a communiqué. Chapter VIII - Languages Rule 34 - Working Languages The working languages of the Commission and of all its institutions shall be those of the Organisation of African Unity. Rule 35 - Interpretation 1. The address delivered in one of the working languages shall be interpreted in the other working languages. 2. Any person addressing the Commission in a language other than one of the working languages, shall, in principle, ensure the interpretation in one of the working languages. The interpreters of the Secretariat may take the interpretation of the original language as source language for their interpretation in the other working languages. Rule 36 - Languages to be Used for Minutes of Proceedings The summary minutes of the sittings of the Commission shall be drafted in the working languages. Rule 37 - Languages to be Used for Resolutions and other Official Decisions All the official decisions and documents of the Commission will be rendered in the working languages. Rule 38 - Tape Recordings of the Session The Secretariat shall record and preserve the tapes of the sessions of the Commission. It may also record and conserve the tapes of the sessions of the committees, working groups and sub-commissions if the Commission so decides. 5