Public authorities can also award contracts by electronic auction. Before starting the auction, they must make a full initial evaluation of the tenders and only allow the admissible ones to take part. The invitation to participate in the auction must state the date and time of the auction and the number of bidding rounds. It should also set out the formula that will determine the automatic rankings. In each bidding round you must be able to see your ranking compared to your competitors, without knowing their identity.
Note: Electronic auctions cannot be used for certain types of contract, such as the design of works (for example architectural plans for a building).