The words “when used in reference to a natural person” are added because of provisions in the title which treat entities as citizens. The words “or an individual citizen of the Trust Territory of the Pacific Islands who is exclusively domiciled in the Northern Mariana Islands within the meaning of section 1005(e) of the Covenant to Establish a Commonwealth of the Northern Mariana Islands in Political Union with the United States of America (48 U.S.C. 1801 note)” are omitted because the Covenant referred to became effective November 4, 1986, making citizens of the Northern Mariana Islands citizens or non-citizen nationals of the United States.