The Kitan (also called Liao) language, an extinct Mongolic language spoken in Northern China, was written using two mutually exclusive scripts, the Kitan Small script and the Kitan Large script. The Kitan Small script was invented by a Kitan scholar known only as Diela, who was inspired by Uyghur writing. It was a mixed script. Phonetic elements were arranged in groups of one to seven to form rectangular phonographic blocks. (Some sources refer to these blocks as polygrams.) These represented the pronunciation of a word, and were used together with a small number of logographic characters that represented frequently used vocabulary. The shapes of some of the Kitan Small logographic characters are the same as some of the Kitan Large characters, but they do not have the same meanings.

Neither of the Kitan scripts has been fully deciphered.