To make my concern clear, Let me give you a scenario.
User A is using Skype for Business and sees an option to call for User B.
User B is not added as a delegate of User A, the question is, why does his name show on User A's Skype account?
I've checked Sefautil to see if User B is added as a delegate at the back end but to no avail.
Please see the images to see the actual screenshot, try to understand as it is written in German.
Image may be NSFW.
Clik here to view.
Image may be NSFW.
Clik here to view.
Image may be NSFW.
Clik here to view.