(a) High school shall mean a nonpublic or public high school which is authorized to issue high school diplomas in accordance with the requirements of section 100.2 of this Title.
(b) Approved substitute assessment shall mean an assessment which is offered by a high school as a substitute for a Regents examination and is approved through a variance granted by the department, pursuant to the requirements of section 100.2(f) of this Title or approved by the department pursuant to section 100.5(d)(4) of this Title.