I find that pages like this: AAIController | Unreal Engine Documentation
are missing a small summary or overview of their role or part… For example, “A player controller is derived from a controller. it’s main purpose is to act on behalf a player (human)… bla bla”.
I guess it would be a bit like Msdn stuff, it attempts to always have a summary of what it’s for… for example: http://msdn.microsoft.com/en-us/library/windows/desktop/bb172256(v=vs.85).aspx
Also it would be amazing to be able to add comments and samples underneath each class… a bit like PHP.net’s documentation 
“user contributed notes”: PHP: usort - Manual
The goal is to have complete descriptions for all classes, variables, functions, etc. Many already have descriptions and should be displayed in the API reference (you can see some on the page you linked). However, we haven’t always been so good at documenting the code in the engine so we are playing a bit of catch-up. Our plan is to hit the most commonly used classes first and continue filling in the rest over time. And hopefully new code added going forward will always have good information.
Sample code is also something we want to add, but we are currently only in the planning stages of how to do that in a way that is maintainable long-term. We will keep you updated as that plan gets more fleshed out.
That’s good enough for me brah. It’s really all very good, just was thinking of some improvements ^_^! Keep up the excellent work!