Constitution of the United Nations Educational, Scientific and Cultural Organization,
Article II, paragraphs 7 and 8:
Each Member State is entitled to appoint a Permanent Delegate to the Organization.
The Permanent Delegate of the Member State shall present his credentials to the Director-General of the Organization, and shall officially assume his duties from the day of presentation of his credentials.
(Paragraph adopted by the General Conference at its 31st session (2001) (31 C/Resolutions, p. 105.)