If the FCC's auction of former UHF bandwidth were to end here, it might raise over $19 billion. But with bidding activity slowing to a crawl, the Commission has one more tool in its arsenal to squeeze out some more value.

Sensing a lull in the action, the handlers for the 700 MHz auction by the US Federal Communications Commission have exercised their discretion, and have moved the auction into what the rules call "Stage Two." In this second -- and, according to the rules, final -- stage, anyone who wants to stay completely in the game must continue bidding no less than 95% of the time, to maintain its full eligibility in later rounds.

"During the second stage of the auction, a bidder desiring to maintain its current bidding eligibility is required to be active on 95 percent of its current bidding eligibility," read the FCC's rules for Auction #73. "Failure to maintain the required activity level will result in the use of an activity rule waiver or, if the bidder has no activity rule waivers remaining, a reduction in the bidder's bidding eligibility in the next round."

An "activity rule waiver" is like a "free-spin" chip that bidders collect, although they have to apply for waivers well in advance. The holder of one of these waivers is entitled to sitting out a round at its discretion. Several waivers were already doled out in January, and by law, the waiver requests must be made public; but since the identities of bidders remain secret, those public postings are almost pointless.

After the end of Round 44 Thursday afternoon, no new bids had been received for the crown jewel nationwide C-block. Stage 45 was set to begin at 4:30 pm EST this afternoon, and with Stage Two rules now in effect, the minimum bid for the C-block was set at just under $4.84 billion. The D-block, meanwhile, remains on the table with its single bid of $472 million.