(1) Nothing in this Part or Part II shall make unlawful the application of any provision (whether in the nature of a requirement, practice or otherwise) such as is mentioned in subsection (2) with respect to -

(a) holding office under, or in the service of, the State (including the Garda Síochána and the Defence Forces) or otherwise as a civil servant, within the meaning of the Civil Service Regulation Act, 1956, or

(b) officers or servants of a local authority, for the purposes of the Local Government Act, 1941, a harbour authority or a health board or a member of staff of an education and training board.

(2) The provisions referred to in subsection (1) are those relating to all or any of the following:

(a) residence;

(b) citizenship;

(c) proficiency in the Irish language.

(3) Nothing in this Part or Part II shall make unlawful the application of any provision (whether in the nature of a requirement, practice or otherwise) in relation to proficiency in the Irish language with respect to teachers in primary and post-primary schools.

(4) Nothing in this Part or Part II shall make it unlawful to require, in relation to a particular post -