The National Security Council (Turkish: Milli Güvenlik Kurulu, MGK) comprises the Chief of Staff, select members of the Council of Ministers, and the President of the Republic (who is also the Commander-in-chief). Like the national security councils of other countries, the MGK develops the national security policy. The policy is expressed in the National Security Policy Document (Turkish: Milli Güvenlik Siyaseti Belgesi), commonly known as "The Red Book". The Red Book is sometimes called the "most secret" document in Turkey. It is updated once or twice a decade.