identification of barreled edible oil in the warehouse: there will be many kinds of food identification, which are generally strictly classified and placed in the warehouse. Non-staple foods (peanut oil, soy sauce, sesame oil, Chili oil, mature vinegar, iced black tea, green tea, etc.) are placed in a fixed range, and the four characters of the non-staple food area are written on the signboard, and so on: the main grain area (rice, wheat flour, sweet potato vermicelli, corn vermicelli, etc.). Generally, this classification method will be adopted in such warehouses.