To avoid any misunderstandings with your bidders, make sure you post your auction rules clearly and early enough for everyone to take a look. It's also a good idea to go over the rules verbally before the onset of the auction. Your auctioneer will go over the actual bidding rules, but it's up to you to set rules about the auction process as a whole. Take some time to consider what works best for your business and then outline these rules clearly for the auction participants.
Some rules that you need to consider are whether or not the bidders are allowed inside the unit or if they have to view from the entrance. You also have to decide how long the winning bidder has to get all of the contents from the unit.