8 C.F.R. § 101.2
An alien who entered the United States as either an immigrant or nonimmigrant under any of the following circumstances shall be regarded as having been lawfully admitted in such status, except as otherwise provided in this part: An alien otherwise admissible whose entry was made and recorded under other than his full true and correct name or whose entry record contains errors in recording sex, names of relatives, or names of foreign places of birth or residence, provided that he establishes by clear, unequivocal, and convincing evidence that the record of the claimed admission relates to him, and, if entry occurred on or after May 22, 1918, if under other than his full, true and correct name that he also establishes that the name was not adopted for the purpose of concealing his identity when obtaining a passport or visa, or for the purpose of using the passport or visa of another person or otherwise evading any provision of the immigration laws, and that the name used at the time of entry was one by which he had been known for a sufficient length of time prior to making application for a passport or visa to have permitted the issuing authority or authorities to have made any necessary investigation concerning him or that his true identity was known to such officials.
8 C.F.R. §101.2