An official language is defined by the Cambridge English Dictionary as, "the language or one of the languages that is accepted by a country's government, is taught in schools, used in the courts of law, etc." Depending on the decree, establishment of an official language might also place restrictions on the use of other languages. Designated rights of an official language can be created in written form or by historic usage.
An official language is recognized by 178 countries, of which 101 recognize more than one. The government of Italy made Italian their official language in 1999, and some nations (such as Mexico and Australia) have never declared de jure official languages at the national level. Other nations have declared non-indigenous official languages.