animating rotation

hey there
I’m just wondering. I have this bottle with some easy mechanism. All objects are parented (from bottom to top in the screenshot) to each other so the position stays accordingly. But for example when I keyframe the rotation of the cap I rotate it around its own Y axis. But in the Graph Editor it shows Euler Z. Not Y as you would expect. In the Dope Sheet it is Y. So why is this not Y in the graph editor? Is it because I rotated it around its own Y axis and not the global Y axis?
When I keyframe both the global and the internal Y axis rotation the graph editor tears apart the connecting line :stuck_out_tongue: