Thread:Support/Language names not in Unicode CLDR/reply (3)

Catalan already has a locale at CLDR.

I think that in order to add Extremaduran to the list of language names which can be localised at CLDR you need to file a ticket to make a change request at CLDR Change Requests. I don't think you need an account to do this. The process for requesting data to be added (to common data I think) is described at "CLDR process". You could try explaining why you want it added to the list of language names.