Free entry of articles in mail articles addressed to diplomatic officers, representatives of certain international organizations, and similar persons is governed by subpart I of part 148 of this chapter. [T.D. 73-175, 38 FR 13369, May 21, 1973, as amended by T.D. 73-227, 38 FR 22548, Aug. 22, 1973; T.D. 78-102, 43 FR 14454, Apr. 6, 1978]