The constitution calls for an independent judiciary. The former northern and southern legal codes have been unified. The legal system includes separate commercial courts and a Supreme Court based in Sana'a. Sharia is the main source of laws, with many court cases being debated according to the religious basis of law and many judges being religious scholars as well as legal authorities. The Prison Authority Organization Act, Republican decree no. 48 (1981), and Prison Act regulations, provide the legal framework for management of the country's prison system.