Example of an auction:
The bid master will begin the auction by setting up the auction environment. Once this has been completed, you will see this (or its current version) in the appropriate chat channel. The message will resemble this:

Private auction is now open for <item link>. Initial bidding will begin at 50. Minimum bid increment is 1. Please /w <bid master> <bid> to place a bid.
Current Bid 50
Current Bid 52
Current Bid 85
Current Bid 85 going ONCE (<item link>)
Current Bid 85 going TWICE (<item link>)
Item <item link> SOLD for 85 to <high bidder>.

Intermixed with these messages you will see your own whispers if you choose to bid on the item.