digraphia

thumb|A digraphic Gaj's Latin alphabet|Latin/Cyrillic street sign in [[Gaboš, Croatia]] thumb|A digraphic Latin/Jawi script|Jawi street sign in [[Pekanbaru, Indonesia]] In sociolinguistics, digraphia refers to the use of more than one writing system for the same language. Synchronic digraphia is the coexistence of two or more writing systems for the same language, while diachronic digraphia or sequential digraphia is the replacement of one writing system by another for a particular language.

Hindustani, with an Urdu literary standard written in Urdu alphabet and a Hindi standard written in Devanagari, is one of the "textbook examples" of synchronic digraphia, cases where writing systems are used contemporaneously. An example of diachronic digraphia, where one writing system replaces another, occurs in the case of Turkish, for which the traditional Arabic writing system was replaced with a Latin-based system in 1928.