(a) In Part 325 of Subchapter A and in this subchapter, unless the context requires otherwise:

(a)(1) Words imparting the singular include the plural;

(a)(2) Words imparting the plural include the singular;

(a)(3) Words imparting the present tense include the future tense.

(b) In this subchapter the word—

(b)(1) Officer includes any person authorized by law to perform the duties of the office;

(b)(2) Writing includes printing and typewriting;

(b)(3) Shall is used in an imperative sense;

(b)(4) Must is used in an imperative sense;

(b)(5) Should is used in a recommendatory sense;

(b)(6) May is used in a permissive sense; and

(b)(7) 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]