Tibetan Buddhist canon
Classical Tibetan was the high register used universally by all Tibetans while the various mutually unintelligible Tibetic languages serve as the low register vernacular, like Central Tibetan language in Ü-Tsang (Tibet proper), Khams Tibetan in Kham, Amdo Tibetan in Amdo, Ladakhi language in Ladakh and Dzongkha in Bhutan. Classical Tibetan was used for official and religious purposes, such as in Tibetan Buddhist religious texts like the Tibetan Buddhist canon and taught and learned in monasteries and schools in Tibetan Buddhist regions.