When I'm abroad, visible under another country's IP address and my system's language is set to English, neither should be used to assign the language. What shou

When I'm abroad, visible under another country's IP address and my system's language is set to English, neither should be used to assign the language. What should be used is locale. Some users may have operating systems in language different to their own but probably more users have proper keyboard language set in their OS. Using IP address to assign the language is the dumbest choice possible but using OS language is not much better.