If a sale is being hosted live or on-line an inventory of all the auction contents needs to be documented to identify each item at the sale. At times items would be brought in on consignment which would be handled separately from the total auction sale. At the time of the inventory lotting an estimate of the value would be determined. A form of inventory would most likely be posted at the sale, given out during the auction registration, a printed item list which would be emailed out to customer email sign-ups. In most cases serial numbers or model numbers are a good source of service to the auction goer. Other forms of item identity is color, brand names, artist name, year, pictures and a little bio about a particular item with detail. Sellers usually are given a inventory list attached to the sellers contract which is a State Law. After the sale is over some lots can be left over which would be brought to a later auction sale or returned to the seller.