A capitonym is a word that changes its meaning if you capitalise it but they sound the same. An example is march and March or herb and Herb. But Polish and polish is unique in that the meaning changes and the pronunciation. Woody (above) is a linguist and professor and he explains that the Polish/polish example doesn’t have a name to distinguish it from other capitonyms and thus called it a capitophone.
Other capitophonic examples he gave include Mobile (the US city) and mobile, Nice (France) and nice (69), and Reading (UK) and reading (what you’re doing right now).
Would Derby/derby count for both (pronounced the same and differently depending on where you’re from)? Slough (UK) and slough would be a capitophone (the latter is pronounced sluff apparently). Isn’t language fun?