I ended with en-DE that for some reason exists. This way my phone has an English interface rather than poorly translated Polish (or worse, one app had English s

I ended with en-DE that for some reason exists. This way my phone has an English interface rather than poorly translated Polish (or worse, one app had English support but displayed Chinese with Polish as system language). And sane units/date formatting etc. I would mildly prefer en-PL, but it does not exist.