§171.9. Rules of construction.
49 C.F.R. § 171.9
In this subchapter, unless the context requires otherwise—
Words imparting the singular include the plural;
Words imparting the plural include the singular; and
Words imparting the masculine gender include the feminine;
In this subchapter, the word—
“Shall” is used in an imperative sense;
“Must” is used in an imperative sense;
“Should” is used in a recommendatory sense;
“May” is used in a permissive sense to state authority or permission to do the act described, and the words “no person may * * ” or “a person may not * *” means that no person is required, authorized, or permitted to do the act described; and
“Includes” is used as a word of inclusion not limitation.
Notes, amendments, and revision history
Amendments
[Amdt. 171-32, 41 FR 15996, Apr. 15, 1976, as amended by Amdt. 171-32A, 41 FR 40630, Sept. 20, 1976; Amdt. 171-121, 58 FR 51528, Oct. 1, 1993; 75 FR 60338, Sept. 30, 2010]
Authority
Authority: 49 U.S.C. 5101-5128, 44701; Pub. L. 101-410 section 4; Pub. L. 104-134, section 31001; Pub. L. 114-74 section 701 (28 U.S.C. 2461 note); 49 CFR 1.81 and 1.97.
Amendments
[Amdt. 171-32, 41 FR 15996, Apr. 15, 1976, as amended by Amdt. 171-32A, 41 FR 40630, Sept. 20, 1976; Amdt. 171-121, 58 FR 51528, Oct. 1, 1993; 75 FR 60338, Sept. 30, 2010]