17.1 Sales by auction involve important economic activity that goes on most weeks at auction houses throughout the UK. A wide variety of assets and securities are the subject-matter of specialist auctions at regular intervals, some firms dealing exclusively with one commodity only. Examples are plant and machinery, livestock, life policies, motor vehicles, firearms, books and postage stamps. In so far as standard conditions of sale exist, at least some of these conditions will vary according to the subject-matter of the auction. Plant and machinery or vehicle sales, for instance, require special conditions of sale to take account of safety legislation. Auctioneers obtain items for their sales from varying sources but primarily from private sellers, personal representatives and traders realising their stock. The auction serves the vital function of reducing assets into money quickly and by a specific date, particularly if no reserve is placed. Sellers, liquidators and receivers often take the view that although prices realised at auction may be lower than in a sale by private treaty, this discount is more than balanced by the saving in administrative effort and time which might be needed to find a suitable private treaty purchaser.