the auction receives a bid during the last 15 minutes, the ending point is delayed to +15 minutes from that bid, until someone being the c.o. for 15minutes wins. This rule applies only in forum auctions.
(Example: Auction ends on 17:00. If any user bids at 16:46, the auction will end when the clock turns 17:01 and not 17:00. If another user bids at 17:00, the auction will end when the clock turns 17:15 and not 17:01 and so on.)