Based on title 18, U.S.C., 1940 ed., § 311 (Mar. 4, 1909, ch. 321, § 188, 35 Stat. 1124).

Reference to persons causing or procuring was omitted as unnecessary in view of definition of “principal” in section 2 of this title.

The punishment provision was rewritten to conform more closely with comparable offenses in other sections. (See sections 1729 and 1730 of this title.)

Minor verbal changes were made.

1994—Pub. L. 103–322 substituted “fined under this title” for “fined not more than $500” in second par.