Hello Mike,
thanks for your reply, I will check the code you mentioned out when I get time. I have worked with some exstentiors before here in Unreal but I wasn’t aware of the code for adding them to the menu. You say that most of the unreal stuff uses them internally. I must have gotten unlucky and only found the place of code where it builds the menus and there weren’t any extensions interfaces in the code as far as I can remember. Anyhow I will check this out :).
About the documentation, yes please, it is definitely lacking in that area of the code. I tried search quite extensively for information about how to add custom right click contextual menus but couldn’t find anything so that is how I decided to invest a couple of hours to see how the actor menu is build and so I hooked into that. 
Chrys