8 U.S.C. § 1302: Registration of aliens

It shall be the duty of every alien now or hereafter in the United States, who (1) is fourteen years of age or older, (2) has not been registered and fingerprinted under section 1201(b) of this title or section 30 or 31 of the Alien Registration Act, 1940, and (3) remains in the United States for thirty days or longer, to apply for registration and to be fingerprinted before the expiration of such thirty days. It shall be the duty of every parent or legal guardian of any alien now or hereafter in the United States, who (1) is less than fourteen years of age, (2) has not been registered under section 1201(b) of this title or section 30 or 31 of the Alien Registration Act, 1940, and (3) remains in the United States for thirty days or longer, to apply for the registration of such alien before the expiration of such thirty days. Whenever any alien attains his fourteenth birthday in the United States he shall, within thirty days thereafter, apply in person for registration and to be fingerprinted. The Attorney General may, in his discretion and on the basis of reciprocity pursuant to such regulations as he may prescribe, waive the requirement of fingerprinting specified in subsections (a) and (b) in the case of any nonimmigrant.