Flag protocol defines the proper placement, handling and use of flags. Some countries have added certain protocols into their law system while others prefer to have "guidelines" without civil or criminal consequences attached. According to United States Code found in Title 4, Chapter 1 pertaining to patriotic customs and observances: §8(k) "The flag, when it is in such condition that it is no longer a fitting emblem for display, should be destroyed in a dignified way, preferably by burning." Alternatives to burning are being investigated, due to the nature of modern materials used in flags, namely nylon, toxic smoke is released when burned.