---
kind: "section"
citation: "49 C.F.R. § 1500.5"
title: "49"
number: "1500.5"
heading: "Rules of construction."
url: "https://uscodex.org/cfr/49/1500.5"
---

# §1500.5. Rules of construction.

- (a) **In this chapter, unless the context requires otherwise—**
  - (1) **Words importing the singular include the plural.**
  - (2) **Words importing the plural include the singular.**
  - (3) **Words importing the masculine sex include the feminine.**
- (b) **In this chapter, the word—**
  - (1) “Must” is used in an imperative sense;
  - (2) “May” is used in a permissive sense to state authority or permission to do the act prescribed, and the words “no person may * * *” or “a person may not * * *” mean that no person is required, authorized, or permitted to do the act prescribed; and
  - (3) “Includes” means “includes but is not limited to”.

## Notes

### Amendments

[67 FR 8351, Feb. 22, 2002, as amended at 90 FR 21690, May 21, 2025]

### Authority

Authority: 49 U.S.C. 114, 5103, 40113, 44901-44907, 44913-44914, 44916-44918, 44935-44936, 44939, 44942, 46105; Pub. L. 110-53 (121 Stat. 266, Aug. 3, 2007) secs. 1408 (6 U.S.C. 1137), 1501 (6 U.S.C. 1151), 1517 (6 U.S.C. 1167), and 1534 (6 U.S.C. 1184).

### Source

Source: 67 FR 8351, Feb. 22, 2002, unless otherwise noted.

### Amendments

[67 FR 8351, Feb. 22, 2002, as amended at 90 FR 21690, May 21, 2025]