The United Nations Conference on Consular Relations was held in Vienna between March 4 and April 22, 1963. The Conference adopted the Vienna Convention on Consular Relations on April 22. The Vienna Convention on Consular Relations was based on a draft contained in the report of the International Law Commission on its thirteenth session. The Convention codified the rules governing consular relations in general: facilities, privileges and immunities relating to consular posts, career consular officers and other members of a consular post, as well as the regime relating to honorary consular officers and consular posts headed by these officers. The preamble simply reiterates that the purpose of consular privileges and immunities is to ensure the efficient functioning of consular posts. The consular premises, their furnishings, the property of the consular post and its means of transport shall be immune from any form of requisition for purposes of national defence or public utility.