(1) Any minimum rate of wages fixed or revised by the appropriate Government in respect of scheduled employments under section 3 may consist of--
         (i) a basic rate of wages and a special allowance at a rate to be adjusted, at such intervals and in such manner as the appropriate Government may direct, to accord as nearly as practicable with the variation in the cost of living index number applicable to such workers (hereinafter referred to as the "cost of living allowance"); or
         (ii) a basic rate of wages with or without the cost of living allowance, and the cash value of the concessions in respect of supplies of essential commodities at concession rates, where so authorised; or
         (iii) an all-inclusive rate allowing for the basic rate, the cost of living allowance and the cash value of the concessions, if any.
     (2) The cost of living allowance and the cash value of the concessions in respect of supplies of essential commodities at concession rates shall be computed by the competent authority at such intervals and in accordance with such directions as may be specified or given by the appropriate Government.