In another non-alliterated words, what it the flow of requests that occur with a user (EUC, not eunich) search with the People Picker Browse Display UI. I was about to try to build this from scratch to make sure that I was troubleshooting the correct boundaries on a recent problem, but, then, BING to the rescue (AGAIN!). The flow diagram of the requests was already out there! YAY to MSDN (http://msdn.microsoft.com/en-us/library/dd357076(PROT.13).aspx ) There is such a wealth of information out there. Especially, on [MS-WSSO]: Windows SharePoint Services Overview. No need to second guess when the protocol is outlined, diagramed, and described in such detail. Enjoy.