Blind Bidding is an item feature that allows bidders to enter their highest bid without being aware of the bids of the other participants. All bid history is hidden from view. When placing a bid, the bidder will be notified if that bid is in the top winning position. If not, they will need to enter a higher bid.
This is most commonly used for items with multiple quantities.
For example, If you have 5 units of an auction item, the 5 highest bidders will win the items with blind bidding enabled.