This got me curious about whether Mongolian has enough Chinese loanwords that it could be written in a mixture of Chinese characters and phonetic script (similar to Japanese). That question led me to this article on the difference between Sino-Xenic and other borrowings from Chinese, using Mongolian as an example: http://www.cjvlang.com/Spicks/sinoxenic.html#nonsinoxenic It mentions in passing that some people in Inner Mongolia do mix Chinese and Mongolian scripts in informal writing.