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(a) In this subchapter, unless the context requires otherwise:
(1) Words imparting the singular include the plural;
(2) Words imparting the plural include the singular; and
(3) Words imparting the masculine gender include the feminine;
(b) In this subchapter, the word: (1) Shall is used in an imperative sense;
(2) Must is used in an imperative sense;
(3) Should is used in a recommendatory sense;
(4) 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
(5) Includes is used as a word of inclusion not limitation.
[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]