Minsk is the capital city of Belarus. Minsk rye is a common rye bread in Belarus named after the city. And it is quite different to most of xUSSR rye breads because it is made using white rye flour instead of a more traditional dark wholegrain rye.
The recipe is known for quite a while now, I have it my Russian book from 1940, I saw it in many bread related blogs and it is present in Ginsberg’s The Rye Baker book as well.