I will try to help.
The surface 5 or 6 custom deals with the surface. I last time I checked was PROBABLY the blue carpet surface. It's really a nice design, but I don't know how to use that for a map due to its unique un-naturalness. I don't know which is which though. If you really wanted to know, test the map by copying and pasting it in the map folder of the Glest directory, then run the Glest program to try out your map.
The object 10 custom could be one of those statues/tortured victims/plant/tree things.
As for resource 1 or 5 custom, it could be a crop (group) of either stone or gold.
The only way to find out what these variables mean is to test them out on the Glest engine.