; (2) officials responsible for enforcing laws related to the regulation of controlled substances (as defined in section 102 of the Comprehensive Drug Abuse Prevention and Control Act of 1970 ( 21 U.S.C. 802 )); and (3) other users of the process. (g) Nature of modifications Modifications made under subsection (e) of this section— (1) may include a system of titling aircraft or registering all aircraft, even aircraft not operated; (2) shall ensure positive, verifiable, and timely identification of the true owner