A proxy bidder represents the interests of a bidder not physically gift at the auction. Typically, the bidder can inform his proxy of the most quantity he's willing to pay, and also the proxy bidder can still raise bids by the predefined bidding increment till either the proxy bidder wins or {the price|the worth|the worth} exceeds the most value of the bidder. If all bidders use a proxy with a predefined most, an English Auction becomes just like a Vickrey Auction.