契丹大字
There are about 15 known monuments with inscriptions in the Khitan large script, ranging in date from 986 to 1176, and about 40 known monuments with inscriptions in the Khitan small script, ranging in date from 1053 to 1171. The two scripts are mutually exclusive (never occurring together on the same monument), but it is not known why the Khitan people used two different scripts, or what determined the choice of which script to use.