the Android phones in Slovakia have a custom locale - en_SK and cs_SK. Language is either Czech or English, location is Slovakia. Now I would like to have strings that target these locales. The default approach is to create a folder "values-CountryCode", for Czech Republic it's values-cs.
But I get a build error if I add a folder name values-en_SK or values-cs_SK: "invalid resource directory name"
What to do?