A winning bidder that qualifies as a small business, as defined in § 90.814(b)(1), or a consortium of small businesses may use a bidding credit of 15 percent to lower the cost of its winning bid on any of the blocks identified in § 90.617(d), Table 4B. A winning bidder that qualifies as a small business, as defined in § 90.814(b)(2), or a consortium of small businesses may use a bidding credit of 10 percent to lower the cost of its winning bid on any of the blocks identified in § 90.617(d), Table 4B.