If you attend an auction in person, you'll need to register as a bidder and you will be given a numbered card or "paddle" to hold up when you bid so that the auctioneer can record who won any particular bid. If you register with "The Saleroom" you will be allocated a bidder number (equivalent to paddle number) which will be recorded with any internet bids you place, whether in advance or live during the auction. This number will show on your screen when you place a bid during live bidding.