Certificate of Loss of Nationality
The Certificate of Loss of Nationality of the United States (CLN) is form DS-4083 of the Bureau of Consular Affairs of the United States Department of State which is completed by a consular official of the United States documenting relinquishment of United States nationality. The form is prescribed by the Secretary of State under the Immigration and Nationality Act of 1952.
A CLN is used only to document a loss of U.S. nationality and it does not affect the loss of U.S. nationality itself. However some provisions of U.S. regulations require a CLN be issued in order to recognize a person as a non-U.S. national even if as a matter of law that person is already provably not a U.S. national. One example of this are FATCA provisions as currently adopted in the US Code of Federal Regulations.
CLNs are applied for and issued at a U.S. consulate or embassy. Persons lacking an alternate nationality or refusing to declare one at the time of application may be listed as being 'stateless' on their CLN.