..That we don't have an exact explanation of what their doctrines are. From what I have observed thus far, it seems that they are very "to themselves" as well, as W.E.B. referred to. 
 
The best resource I have found regarding their beliefs is a website at www.fldstruth.com. I have read through it, but couldn't really find any difinitive beliefs spelled out, or reasons for their practices that we view as "different".