I was looking through forums to find a place for my feedback, but didn't found it and I didn't find report button in the online documentation which uses to report a issue. Maybe it is my fault.
I'll post my thoughts here, then.
I was reading Urho.ElementMask and to figure out which value each enum has I should go to the original Urho3d source file, also you may look at UrhoSharp source file to see how it properly displayed.
I just want to post a thought, that Xamarin documentation could be better if enums were displayed sorted and with their values.