1970—Pub. L. 91–579 inserted references to exhibitors and inserted proviso that operators of auction sales subject to section 2142 of this title shall not be required to comply with the provisions of this section.

Amendment by Pub. L. 91–579 effective one year after Dec. 24, 1970, see section 23 of Pub. L. 91–579, set out as a note under section 2131 of this title.