I just saw something that I found really strange, I looked at the fifth tier barrack upgrade for Prussia and it had a unit called "Superior Line Infantry" that I am pretty sure I've never seen before.
So where does this unit come from? 1.5? Or was it in before 1.1 or 1.2 and just now returned? Has anyone else seen it?

I'm sorry if it seems like a stupid question but I played as Prussia twice before and am pretty sure I could never recruit this unit.