Registered persons shall notify the appropriate ATF officer in writing, in duplicate, of significant changes in the information set forth in their registration (Approved by the Office of Management and Budget under control number 1140-0009) [T.D. ATF-8, 39 FR 3251, Jan. 25, 1974, as amended by T.D. ATF-215, 50 FR 42161, Oct. 18, 1985; ATF-11F, 73 FR 57240, Oct. 2, 2008]