39 CFR 320.1 - Definitions.
The definitions in § 310.1 apply to part 320 as well. 1
1 Several of the items enumerated in § 310.1(a)(7) do not self-evidently lie outside of the definition of “letter”. To the extent, however, that there is any question whether these items may properly be excluded by definition, the Postal Service has determined by adoption of these regulations that the restrictions of the Private Express Statutes are suspended pursuant to 39 U.S.C. 601(b).