The "book" originated from the government's specific report on a specific issue. Usually, the report was printed without any decoration, and the cover was also black and white, so it was called "white book." In many countries, it has become a convention for the government to use the "white book" when publishing reports. For example, the "China's Regional National Autonomy" published by China and the "China National Defense White Paper 2004". In addition, some countries use the "Red Book", "Blue Book", "Green Book" and other forms. The nature of the "official commentary" of the "book" also makes it often associated with "authority."