thanks for pointing me to page 9.
I found the icon there. Funny I didn't see it when I skimmed over this exact page
I will have to look at this a little deeper, because I think I haven't seen this icon before on these classes. None of them are GUI classes.
I cannot say right now if my image is corrupt or something. I'll have to compare with another image (at work). If it's just in this one image I'll simply not think about it any more...