From the most recent PBS newsletter:


WAIVES REVISITED
...
Where this has the least desirable impact is when bidders use waives in their final submitted bid group and they enter completion mode. Waives are not stripped out during completion mode, and if a bidder makes it to completion mode four due to not bidding deep enough, they are subject to an award that not only includes trips they preferred not to fly, but which uses the waives to decrease line quality even further.

So, if you are going to use a "waive" in your bidding strategy, make sure you don't keep the waive in the last one!!!!