8 A supply, other than a zero-rated supply, made by a government, a school authority, a vocational school, a public college or a university of a service of instructing individuals in, or administering examinations in respect of, courses leading to certificates, diplomas, licences or similar documents, or classes or ratings in respect of licences, that attest to the competence of individuals to practise or perform a trade or vocation, except where the supplier has made an election under this section in prescribed form containing prescribed information.