[Edratman]

I am now confused by the masks.

What is the difference between "site location masks" and "terrain masks"?

When I open a map file I see, for example,

"#terrain 331 4194312"

Which category does "4194312" fall into?

I have never typed in that number. Whenever I want to change terrain types I just open the map editor and click away. (I'm a little less fastidious about province colors than most.)