Tatar, along with Russian, is the official language of the Republic of Tatarstan. The official script of Tatar language is based on the Cyrillic script with some additional letters. The Republic of Tatarstan passed a law in 1999, which came into force in 2001, establishing an official Tatar Latin alphabet. A Russian federal law overrode it in 2002, making Cyrillic the sole official script in Tatarstan since. Unofficially, other scripts are used as well, mostly Latin and Arabic. All official sources in Tatarstan must use Cyrillic on their websites and in publishing. In other cases, where Tatar has no official status, the use of a specific alphabet depends on the preference of the author.