The Equal Opportunity Act 1984 (SA), can be found here:
http://www.austlii.edu.au/au/legis/sa/consol_act/eoa1984250/
This act covers discrimination on a number of grounds and in a number of areas. The pertinent ground and area for the girl school uniform debate is sex and education.
While we encourage you to peruse the legislation document, we have outlined below the crucial areas for the girl school uniform debate:
Relevant sections for school uniforms:
Section 29 — Criteria for discrimination on ground of sex, sexual orientation or gender identity
(2) For the purposes of this Act, a person discriminates on the ground of sex—
(a) if he or she treats another unfavourably because of the other’s sex; or
(b) if he or she treats another unfavourably because the other does not comply, or is not able to comply, with a particular requirement and—
(i) the nature of the requirement is such that a substantially higher proportion of persons of the opposite sex complies, or is able to comply, with the requirement than of those of the other’s sex; and
(ii) the requirement is not reasonable in the circumstances of the case; or
(c) if he or she treats another unfavourably on the basis of a characteristic that appertains generally to persons of the other’s sex, or on the basis of a presumed characteristic that is generally imputed to persons of that sex; or
(d) if he or she treats another unfavourably because of an attribute of or a circumstance affecting a relative or associate of the other, being an attribute or circumstance described in the preceding paragraphs.
Section 37 – Discrimination by educational authorities
(2) It is unlawful for an educational authority to discriminate against a student on the ground of sex, sexual orientation or gender identity—
(a) in the terms or conditions on which it provides the student with training or education; or
(b) by denying or limiting access to a benefit provided by the authority; or
(c) by expelling the student; or
(d) by subjecting the student to other detriment.