390.7 Rules of construction.§ 390.7 Rules of construction.
(a) In part 325 of subchapter A and in this subchapter, unless the context requires otherwise:
(1) Words imparting the singular include the plural;
(2) Words imparting the plural include the singular;
(3) Words imparting the present tense include the future tense.
(b) In this subchapter the word -
(1) Officer includes any person authorized by law to perform the duties of the office;
(2) Shall is used in an imperative sense;
(3) Must is used in an imperative sense;
(4) Should is used in a recommendatory sense;
(5) May is used in a permissive sense; and
(6) Includes is used as a word of inclusion, not limitation.[53 FR 18052, May 19, 1988, as amended at 60 FR 38744, July 28, 1995; 83 FR 16226, Apr. 16, 2018]