(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 gender 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''.