{"data":{"id":"us/49-cfr-1500.5","jurisdiction":"us","citation":"49 CFR 1500.5","heading":"Rules of construction.","body":"(a) In this chapter, unless the context requires otherwise:\n(1) Words importing the singular include the plural.\n(2) Words importing the plural include the singular.\n(3) Words importing the masculine sex include the feminine.\n(b) In this chapter, the word:\n(1) “Must” is used in an imperative sense;\n(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\n(3) “Includes” means “includes but is not limited to”.","path":["Title 49—Transportation","Subtitle B—Other Regulations Relating to Transportation","CHAPTER XII—TRANSPORTATION SECURITY ADMINISTRATION, DEPARTMENT OF HOMELAND SECURITY","SUBCHAPTER A—ADMINISTRATIVE AND PROCEDURAL RULES","PART 1500—APPLICABILITY, TERMS, AND ABBREVIATIONS"],"source_url":"https://www.ecfr.gov/api/versioner/v1/full/2026-08-25/title-49.xml","current_through":"2026-08-25","vintage":"","retrieved_at":"2026-08-27T02:26:34Z","sha256":"19e4da7f18f1ce43d43bd454c7680df55ab8cb791faaabf37dda6a6038acd5b9","source_id":"us-cfr","stale":true,"prev":"us/49-cfr-1500.3","next":"us/49-cfr-1502.1"},"notice":"GroundRules: Original legal text. Not legal advice."}