(1) The singular number includes the plural and the singular, and the plural the singular, unless the context clearly indicates the contrary.

(2) Words used in the present tense include the past and future tenses, and the future present.

(3) The word "shall" is a mandatory requirement. The word "may" is a permissive requirement. The word "should" is a preferred requirement.

(4) The word "building" or "structure" includes any part thereof, and the word "structure" includes the word "building."

(5) Words not defined herein but defined in the subdivision control ordinance shall be interpreted in accordance with the subdivision control ordinance definitions.

(6) Words and terms not defined herein or in the subdivision control ordinance shall be interpreted in accord with their normal dictionary meaning and customary usage.