There are standards for tagging and classification of Bulgarian roads:
https://wiki.openstreetmap.org/wiki/Bg:WikiProject_Bulgaria/%D0%9F%D1%8A%D1%82%D0%BD%D0%B0_%D0%BC%D1%80%D0%B5%D0%B6%D0%B0

You might also search for several discussions on this topic here:https://community.openstreetmap.org/c/communities/bg/75

I'll have to revert this changeset