YuMi's arm angle definition

We've recently acquired four single-arm YuMis for our undergraduate robotics course, in addition to our IRB 1600. I am preparing the modifications for my course, and I just can't get over the fact that there is virtually zero mention of YuMi in ABB programming documentation. For example, there is no mention of the "arm angle" in the definition of a robtarget. In fact, there is absolutely no mathematical definition of the arm angle. Am I missing a manual???