Tibetan is an official language of the Tibet Autonomous Region of the People's Republic of China. Standard Tibetan is the most widely spoken form of the Tibetic languages. Classical Tibetan refers to the language of any text written in Tibetan after the Old Tibetan period and before the modern period. Tibetan is written with an Indic script, with a historically conservative orthography that reflects Old Tibetan phonology and helps unify the Tibetan-language area. Unlike many other languages of East Asia, there are no numeral auxiliaries or measure words used in counting in Tibetan, although words expressive of a collective or integral are often used after the tens, and sometimes after a smaller number. The written language is based on Classical Tibetan and is highly conservative.