The idea is that you can
1) Assign fills to only work in certain situations. For example, you want your brick elevation fill to only be usable in drafting fills or cover fills, but not section fills.
2) use Display options to set each type of fill to be off, bitmap, or vector.
Drafting fills are the default type placed with the fill tool. Cover fills are placed on slabs, roofs, and meshes in plan view. Cut fills are generated when a section cuts through an element.
I hope that makes sense!
Tom Waltz
