Firman
A firman, farman (Persian: فرمان farmân) or ferman (Turkish) at the constitutional level was a royal mandate or decree issued by a sovereign in certain historical Islamic states, including the Ottoman Empire, Mughal Empire, State of Hyderabad, and Iran under Shah Mohammed Reza Pahlavi. During various periods they were collected and applied as traditional bodies of law. The word firman comes from the Persian: farmân فرمان meaning "decree" or "order". In Turkish it is called a ferman.
On a more practical level, a firman was, and may still be, any written permission granted by the appropriate Islamic official at any level of government. Westerners are perhaps most familiar with the permission to travel in a country, which typically could be purchased beforehand, or the permission to conduct scholarly investigation in the country, such as archaeological excavation. Firmans may or may not be combined with various sorts of passports.
Origins of firmans in the Ottoman Empire
In the Ottoman Empire, the Sultan derived his authority from his role as upholder of the Shar'ia, but the Shar'ia did not cover all aspects of Ottoman social and political life. Therefore, in order to regulate relations and status, duties and dress of aristocracy and subjects, the Sultan created firmans.