33 CFR 141.30 - Evidence of status as a resident alien.
For the purposes of this part, the employer may accept as sufficient evidence that a person is a resident alien any one of the following documents and no others:
(a) A valid merchant mariner's document issued by the Coast Guard.
(b) An alien registration receipt card issued by the Immigration and Customs Enforcement Agency certifying that the card holder has been admitted to the United States as an immigrant.
(c) A declaration of intention to become a citizen of the United States issued by a Naturalization Court.