Mendix has the possibility to switch languages. When adding a language you can only choose from the ISO languages. For one of our apps we need to define an alternate language set for a specific organization. They use different terminology within their company then the company the application was originally build for. Is there a possibility to define a custom language other than the existing ISO languages Could also be usefull for implementing language sets for dialects.
You can't define your own language, but you can use one of the languages for the usergroup that has different terminology. For example use nlNL as the standard language and nlBE for the other group.