48 C.F.R. §§ 52.214-6
As prescribed in 14.201-6(c)(2), insert the following provision:
Explanation to Prospective Bidders (APR 1984)
Any prospective bidder desiring an explanation or interpretation of the solicitation, drawings, specifications, etc., must request it in writing soon enough to allow a reply to reach all prospective bidders before the submission of their bids. Oral explanations or instructions given before the award of a contract will not be binding. Any information given a prospective bidder concerning a solicitation will be furnished promptly to all other prospective bidders as an amendment to the solicitation, if that information is necessary in submitting bids or if the lack of it would be prejudicial to other prospective bidders.
(End of provision)
48 C.F.R. §§52.214-6