Market ouvert
（重定向自Market overt）
Market overt or Marché ouvert (Law French for "open market") was an English legal concept originating in mediaeval times governing subsequent ownership of stolen goods.
In general, the sale of stolen goods does not convey effective title. However, under 'marché ouvert', if goods were openly sold in designated markets between sunrise and sunset, provenance could not be questioned and effective title of ownership was obtained. The law originated centuries ago when people did not travel; if the victim of a theft did not bother to look in his local market on market day—the only place where the goods were likely to be—he was not being suitably diligent.