8 U.S.C. § 1304 : US Code - Section 1304: Forms for registration and fingerprinting

    (a) Preparation; contents
      The Attorney General and the Secretary of State jointly are
    authorized and directed to prepare forms for the registration of
    aliens under section 1301 of this title, and the Attorney General
    is authorized and directed to prepare forms for the registration
    and fingerprinting of aliens under section 1302 of this title. Such
    forms shall contain inquiries with respect to (1) the date and
    place of entry of the alien into the United States; (2) activities
    in which he has been and intends to be engaged; (3) the length of
    time he expects to remain in the United States; (4) the police and
    criminal record, if any, of such alien; and (5) such additional
    matters as may be prescribed.
    (b) Confidential nature
      All registration and fingerprint records made under the
    provisions of this subchapter shall be confidential, and shall be
    made available only (1) pursuant to section 1357(f)(2) of this
    title, and (2) to such persons or agencies as may be designated by
    the Attorney General.
    (c) Information under oath
      Every person required to apply for the registration of himself or
    another under this subchapter shall submit under oath the
    information required for such registration. Any person authorized
    under regulations issued by the Attorney General to register aliens
    under this subchapter shall be authorized to administer oaths for
    such purpose.
    (d) Certificate of alien registration or alien receipt card
      Every alien in the United States who has been registered and
    fingerprinted under the provisions of the Alien Registration Act,
    1940, or under the provisions of this chapter shall be issued a
    certificate of alien registration or an alien registration receipt
    card in such form and manner and at such time as shall be
    prescribed under regulations issued by the Attorney General.
    (e) Personal possession of registration or receipt card; penalties
      Every alien, eighteen years of age and over, shall at all times
    carry with him and have in his personal possession any certificate
    of alien registration or alien registration receipt card issued to
    him pursuant to subsection (d) of this section. Any alien who fails
    to comply with the provisions of this subsection shall be guilty of
    a misdemeanor and shall upon conviction for each offense be fined
    not to exceed $100 or be imprisoned not more than thirty days, or
    both.
    (f) Alien's social security account number
      Notwithstanding any other provision of law, the Attorney General
    is authorized to require any alien to provide the alien's social
    security account number for purposes of inclusion in any record of
    the alien maintained by the Attorney General or the Service.