I've just earned a badge in this popular question I wrote 15 months ago in SuperUser Community. And it attracted me because, even after all this time and 1000 views, it stills not-answered. Thus I got that I questioned it in the wrong community, probably in AskUbuntu it wouldn't stayed so much time untouched.

So I would like to understand what is the policy over transfer questions between communities and how I could achieve it

I checked Transfering a question from Ask Ubuntu to Super User, but there's also no answers there