Lack of documentation was always one of the few big weakness of vBulletin. When I asked for developer documentation, I was pointed (with a straight face) to the index-like API, or the very beginner-level PHP examples at vB.org, or even better, I was told to read the code and figure it out myself.
I am not saying I need a walkthrough of the code, but knowing what the basic functions expect, return, etc. beyond just a list of variables and parameters would be most helpful. I wasted 20 minutes one day figuring out that the variable I needed to reset was in the Datastore, and another 20 minutes figuring out how to force a rebuild of the Datastore. This is the kind of thing that should have been in a beginner vB coding tutorial.
