Section 27(3) in The Bureau of Indian Standards Rules, 2018
(3)The Foreward of the provisional Indian Standard shall specify the following, namely:-(i)need for preparing the provisional Indian Standard;(ii)scope of its application; and(iii)period of its validity:Provided that the provisional Indian standards so notified under sub-rule (2) shall be valid for a period upto two years, as may be determined by the Bureau on the recommendations of the sectional committee, and may be extended by not more than two years.
