New EU members would have to adhere to the following framework (Convention for the Protection of National Minorities 1994 ):
- Article 10: Right to use the minority language in administration and justice
- Article 11: Right to display local names, street names and other topographical indications in the minority language
- Article 12: Right to learn and receive instruction in one’s minority language
Due to being part of Spain (which gets to play by the old rules), Catalonia can ignore these provisions and also pretty much ignore its(substantial) Spanish speaking minority. However, as its own country and (presumably) new EU member, it would be unlikely that these rules could be ignored, and Catalonia could find itself in the position where it needs to provide more services in Spanish that it currently does.