 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.In addition to monumental inscriptions, short inscriptions in both Khitan scripts have also been found on tomb murals and rock paintings, and on various portable artefacts such as mirrors, amulets, paiza (tablets of authority given to officials and envoys), and special non-circulation coins.A number of bronze official seals with the seal face inscribed in the Khitan large script are also known.