 Mongolian names of Tibetan origin are usually restricted to people in their 50s and older.Because China does not recognize Mongolian clan names, Mongols in China who have acquired their passports since 2001 have "XXX" printed in place of their surnames, while before not only "XXX" but also a syllable from an individual's given name or the first syllable of the patronymic was used in place of the Chinese surname.Also, for some individuals, "XXX" is printed in the slot for the given name, while the given name is printed in the slot for the surname.