4. The classification of each such school as—
(a)a county, voluntary controlled, voluntary aided or special agreement school;
(b)a primary, middle or secondary school;
(c)a comprehensive, secondary modern, grammar or bilateral school;
(d)a co-educational or single-sex school;
(e)a day or boarding school or a school taking both day and boarding pupils;
except that for the purposes of sub-paragraphs (b) and (c) other terminology may be used according to usage in the authority.