UNTC

see article 21 which reads as follows: "(a) These terms of reference shall enter into force when States together accounting for at least 70 per cent of trade in tin, as set out in the annex to these terms of reference, have notified the Secretary-General of the United Nations (hereinafter referred to as "the depositary") pursuant to subparabraph (b) below of their acceptance of these terms of reference. (b) Any State or any intergovernmental organization referred to in paragraph 5 which desires to become a member of the Group shall notify the depositary that it accepts these terms of reference either provisionally, pending the conclusion of its internal procedures, or definitively. Any State or intergovernmental organization which has notified its provisional acceptance of these terms of reference shall endeavour to complete its procedures as quickly as possible and shall notify the depositary of their completion. (c) If the requirements for entry into force of these terms of reference have not been met on 31 December 1989, the depositary shall invite those States and intergovernmental organizations that have notified their acceptance of these terms of reference pursuant to subparagraph (b) above to decide whether or not to put these terms of reference into force among themselves. (d) When these terms of reference enter into force, the depositary shall convene an inaugural meeting of the Group as soon as possible thereafter. Members shall be notified at least one month, where possible, prior to that meeting.".