The Secretariat is a principal organ of the United Nations. Articles 7-8, 97-101 of the UN Charter primarily concern the Secretariat. Other Articles of the Charter may also relate to the work of the Secretariat.
The Secretary-General heads the Secretariat as the chief administrative officer of the Organization. The Secretary-General is appointed by the General Assembly upon the recommendation of the Security Council.
The Secretariat provides service to the other principal organs and carries out the work mandated by them. The Secretariat is organized in departments and offices according to the changing needs of the Organization. Over time, the structure and functions of the Secretariat have changed.
Staff Regulations are established by the General Assembly and promulgated by the Secretary-General. The Staff Regulations require the Secretary-General to provide and enforce Staff Rules, consistent with the Staff Regulations. The declaration made by staff (formerly the oath of office) is part of the Staff Regulations.