If a qualified bidder is in doubt as to the meaning of any data or requirements or any part of the bidding documents, written request may be submitted to the PBAC for an interpretation of the same, allowing sufficient time to reply before the submission of his bid. Any substantive interpretation given shall be issued in the form of a Supplemental Notice and furnished to all bidders. The PBAC may also issue Supplemental Notices to all bidders any time for purposes of clarifying any provisions of the bidding documents provided that the same is issued within a reasonable period to all bidders to consider the same in the preparation of their bids. Receipt of all Supplemental Notices shall be duly acknowledged by each bidder prior to the submission of his bid and shall be so indicated in the bid.