Map #17 is CoronaColor texmap set to whatever colour you need for the background (in this case - pure white).
CoronaBitmap contains HDRI, which is used for scene lighting (could be ommited if you're using other means to light your scene).
Green dots are just a part of 3ds Max's UI, they show which maps are connected to which slots.
I don't know how much C4D UI differs from 3ds Max, so i can't help you much more than that, sorry.