+1 indeed, but I think most of people have already a hard time to see why we need to make the difference between country code and language code, and even more that something that people consider as a "dialect" can actually be a totally different language (for example in China a lot of "dialect/fangyang" are actually not dialect of Mandarin, for example Shanghainese (Wu language) and languages from Hunan province)

after you can also try to explan them that the common "represent a language by a flag" becomes quickly broken and subject to strong arguing between people (what flag do you put for Tibetan language for example? or for each of Indian languages)