Agreed, although if you are clever, you can look at different tiles and make a list for yourself. I believe 64 is ramps, and 2 is foundation I think? or was it wall. Anyway, I was messing around with them and the tiles have the flags set on them so you can at least make a little list for yourself.
It would be nice to see this exposed as an enumeration with selectable values, make the editor a bit easier to use at a glance, but I have some bigger beefs first 