The document discusses wallpaper data and symbols, which provide important information for applying wallpaper properly. It explains that manufacturers' data sheets contain details about a paper's properties and instructions for use, including application methods, adhesive types, and symbols indicating the paper's pattern, batch number, cleanability, light-fastness, removal method, matching technique, hanging direction, design repeat, and coordinating fabrics. Correct interpretation of these symbols is necessary for successful wallpaper installation.