For a ball valve, open position is normally with the handle parallel to the pipe. The only thing that makes sense is your handle turned independent of the valve somehow. Most metal valves have a keyed hole and shaft, so this shouldn't be possible. I think pvc valves have the handle press fit with an indexed shaft, so same thing there.

Really, it doesn't matter. If someone opens it they can figure out that it needs to turn 90° no matter what direction it's facing.