(1) “Board” means a board of education of a reorganized school district.

(2) “Teacher” means any certificated professional employee of a public school district. It shall not include a person employed as assistant principal, principal, supervisor, administrative assistant, director, assistant superintendent or superintendent; except that any such person who has completed 3 years of service in the State, 2 years of which shall have been in the employ of the same board, may at that person's own option elect to be assigned as a teacher in the employ of said board.