Artikel 21

1. The present Convention may be revised by the General Conference of the United Nations Educational, Scientific and Cultural Organization, any such revision, however, binding only those States which shall become parties to the revising convention.
2. Should the General Conference adopt a new convention revising the present Convention in whole or in part, and unless the new convention otherwise provides, the present Convention shall cease to be open to ratification, acceptance or accession as from the date when the new revising convention enters into force.