For the purposes of Sections 207 and 214 a school of “less than collegiate grade” is (a) any institution of learning attendance at which exempts a student from attendance at a public full-time elementary or secondary day school under Section 48222 of the Education Code or (b) any institution of learning a majority of whose students are persons that have been excused from attendance at a full-time elementary or secondary day school under Section 48221 or 48226 of the Education Code.