In the course of the Russian municipal reform of 2004–2005, all federal subjects of Russia were to streamline the structures of local self-government, which is guaranteed by the Constitution of Russia. The reform mandated that each federal subject was to have a unified structure of the municipal government bodies by 1 January 2005, and a law enforcing the reform provisions went in effect on 1 January 2006. According to the law, the units of the municipal division (called "municipal formations") are as follows:[6]