There are some ntdll calls that are officially documented and ok to use. Of course there are also a lot of calls you shouldn't use. When necessary, it's fine t

There are some ntdll calls that are officially documented and ok to use. Of course there are also a lot of calls you shouldn't use. When necessary, it's fine to use even undocumented ones to support Windows 7 and older. It's not like those are going to change anymore.