The traditional Mongolian script, also known as the Hudum Mongol bichig, was the first writing system created specifically for the Mongolian language, and was the most widespread until the introduction of Cyrillic in 1946. The script is a co-official script in Mongolia since 2025, alongside the Cyrillic script for the language. It is also the official written form being taught in schools for Mongolian ethnic students in the Inner Mongolia Autonomous Region of the People's Republic of China. It is traditionally written in vertical lines from top to bottom, flowing in lines from left to right . Derived from the Old Uyghur alphabet, it is a true alphabet, with separate letters for consonants and vowels. It has been adapted for such languages as Oirat and Manchu. Alphabets based on this classical vertical script continue to be used in Mongolia and Inner Mongolia to write Mongolian, Xibe and, experimentally, Evenki.