The European Charter for Regional or Minority Languages is the European convention for the protection and promotion of languages used by traditional minorities. Together with the Framework Convention for the Protection of National Minorities it constitutes the Council of Europe’s commitment to the protection of national minorities. Regional or minority languages are part of Europe’s cultural heritage and their protection and promotion contribute to the building of a Europe based on democracy and cultural diversity.
The Charter, drawn up on the basis of a text put forward by the Standing Conference of Local and Regional Authorities of Europe, was adopted as a convention on 25 June 1992 by the Committee of Ministers of the Council of Europe, and was opened for signature in Strasbourg on 5 November 1992. It entered into force on 1 March 1998.
https://www.coe.int/en/web/european-charter-regional-or-minority-languages/about-the-charter