For purposes of this section, the following words shall be construed as follows:
(a) "Rehabilitation teacher" means any person employed by the division and who meets the certification requirements of section two-a, article three, chapter eighteen-a of this code, or who has been certified to teach by a state or nationally recognized organization, as approved by the office of the secretary ofeducation and the arts. Such teachers shall maintain current certification in their teaching areas in order to remain employed. Such persons also shall teach only in the areas in which they are certified: Provided, That teachers who were employed on or before the first day of April, one thousand nine hundred ninety-five, shall be exempt from the following requirements: (1) Certification pursuant to section two-a, article three, chapter eighteen-a of this code; (2) maintenance of current certification in their teaching areas in order to remain employed; and (3) teaching only in the areas in which they are certified.
(b) "Equivalent rate of pay" means an annualized rate based on a two hundred forty-day teaching schedule and includes pay for vacation and legal state holidays.