The Iraqi Turkmen/Turkoman share close cultural and linguistic ties with Turkey, particularly the Anatolian region. They are predominately Muslims, formed of a majority Sunni population (about 60%-70%) but there is also a significant number of Turkmen/Turkoman practicing the Shia branch of Islam (about 30% to 40%). Nonetheless, the Turkmen are mainly secular, having internalized the secularist interpretation practiced in the Republic of Turkey. The minority speak their own dialect of Turkish, which is often called "Turkmen". This dialect was influenced by Ottoman Turkish from 1534 onwards, but also by Persian during the brief capture of Baghdad in 1624; thereafter, in 1640, the Turkish varieties continued to be influenced by Ottoman Turkish, as well as other languages in the region, such as Arabic and Kurdish. Some linguists have suggested that the dialect spoken by Turkmen/Turkoman is similar to the South Azeri dialect used by the Turkish Yörük tribes in the Balkans and Anatolia. However, the Turkmen/Turkoman dialect is particularly close to the Turkish dialects of Diyarbakır and Urfa in south-eastern Turkey and Istanbul Turkish has long been the prestige dialect which has exerted a profound historical influence on their dialect. In addition, the Iraqi Turkmen/Turkoman grammar "differs sharply" from Irano-Turkic varieties, such as South Azeri and Afshar types. In 1997 the Turkmen/Turkoman adopted the Turkish alphabet as the formal written language and by 2005 the community leaders decided that the Turkish language would replace the Arabic script in Iraqi schools. The current prevalence of satellite television and media exposure from Turkey may have also led to the standardisation of Turkmeni towards Turkish, and the preferable language for adolescents associating with the Turkish culture.