Section 12(3) in The Standards of Weights and Measures (National Standards) Rules, 1988
(3)On the expiry of the period of aforesaid five years, the use of coefficient and their respective symbols as specified in Schedule X shall be compulsory.Explanation.-In the case of a coefficient the use of which is permissible under any of the provisos to sub-rule (2), the symbol, if any, attached to such coefficient may also be used for the same period for which the corresponding coefficient is permitted to be used.
