The following words and phrases when used in this article shall have the meanings given to them in this section unless the context clearly indicates otherwise:
"Department." The Department of Education of the Commonwealth.
"Eligible teacher." A teacher who:
"National Board for Professional Teaching Standards" or "NBPTS." The independent, nonprofit organization established in 1987 to establish high standards for teachers' knowledge and performance and for the development and operation of a national voluntary system to assess and certify teachers who meet those standards.
"Public school." A school operated by a school district, intermediate unit, charter school, cyber charter school or an area career and technical school.
24 P.S. § 11-1101-B