Explanation.—For the purposes of this article and article 16, "economically weaker sections" shall be such as may be notified by the State from time to time on the basis of family income and other indicators of economic disadvantage.] 16. Equality of opportunity in matters of public employment.—(1) There shall be equality of opportunity for all citizens in matters relating to employment or appointment to any office under the State. (2) No citizen shall, on grounds only of religion, race, caste, sex, descent, place of birth, residence or any of them, be ineligible for, or discriminated against in respect of, any employment or office under the State. (3) Nothing in this article shall prevent Parliament from making any law prescribing, in regard to a class or classes of employment or appointment to an office 1[under the Government of, or any local or other authority within, a State or Union territory, any requirement as to residence within that State or Union territory] prior to such employment or appointment. (4) Nothing in this article shall prevent the State from making any provision for the reservation of appointments or posts in favour of any backward class of citizens which, in the opinion of the State, is not adequately represented in the services under the State. 2 [(4A) Nothing in this article shall prevent the State from making any provision for reservation 3 [in matters of promotion, with consequential seniority, to any class] or classes of posts in the services under the State in favour of the Scheduled Castes and the Scheduled Tribes which, in the opinion of the State, are not adequately represented in the services under the State.] 4 [(4B) Nothing in this article shall prevent the State from considering any unfilled vacancies of a year which are reserved for being filled up in that year in accordance with any provision for reservation made under clause (4) or clause (4A) as a separate class of vacancies to be filled up in any succeeding year or years and such class of vacancies shall not be considered together with the vacancies of the year in which they are being filled up for determining the ceiling of fifty per cent. reservation on total number of vacancies of that year.] 1. Subs. by the Constitution (Seventh Amendment) Act, 1956, s. 29 and Sch., for "under any State specified in the First Schedule or any local or other authority within its territory, any requirement as to residence within that State" (w.e.f. 1-11-1956). 2. Ins. by the Constitution (Seventy-seventh Amendment) Act, 1995, s. 2 (w.e.f. 17-6-1995). 3. Subs. by the Constitution (Eighty-fifth Amendment) Act, 2001, s. 2, for certain words (retrospectively) (w.e.f. 17-6-1995). 4. Ins. by the Constitution (Eighty-first Amendment) Act, 2000, s. 2 (w.e.f. 9-6-2000). 39