The Education (School Curriculum and Related Information) (Wales) Regulations 1991

4.  The classification of each such school as:–

(a)a county, controlled, aided or special agreement school;

(b)a primary, middle or secondary school or a sixth form college;

(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.