Except where specifically defined herein, all words used in the Subdivision Regulations shall carry customary meanings. Words used in the present tense include the future tense; the plural includes the singular and the singular includes the plural; the word "lot" includes the word "parcel" and "plot"; the word "building" includes the word "structure"; the word "shall" is mandatory, the word "may" is permissive, and the word "should" is preferred; the words "used" or "occupied" include the words "intended, designed or arranged to be used or occupied"; and the word "person" includes a firm, association, organization, partnership, trust, company, or corporation as well as an individual. Words denoting the masculine gender shall be deemed to include the feminine and neuter genders. A general term following specific enumeration of terms is not to be limited to the class enumerated unless expressly so limited.