The term dates from the nineteenth century. If defines a set of signs capable of expressing with a certain degree of accuracy the future. Focusing the evolution of style means drawing a number of trends. More than theories on the origins of processes — imitation, distinction, identification, differentiation, and conformism — this is a matter of constructing flows of orientations that determine fashions. Each link in the production chain involves specialists and industrialists in the textile and apparal manufacturing process, working hard to reduce the risks of error. For each transition, then, devices are activated to identify trends developed through concerted actions, periodical consultations with experts of various countries, members of bureaux de style of the comité de mode. From these exchanges, the cahiers de tendences are developed, which contain illustrations of materials, forms, and colors of the new orientations, more or less accurate, checked totally or partially by the manufacturers of fibers, fabrics, threads, and apparel, with advantage of putting one’s products in line with general trends, and launching trend-setting lines.