The advertisements of a chicken restaurant in Tainan are distributed in various areas in the forms like iron sheets at a construction site or wasteland. They can be found at almost all demolition and construction sites. As they are posted in an irregular manner and at bleak places, they seem not directly serve the function of introducing the restaurant. It is difficult to tell if they are unified backgrounds made by iron sheets, or the trademark of iron sheet. The observers were asked to track the iron sheets.