Attached Link: Wavefront OBJect File Format Specs

I was reading through te Wavefront OBJect file format specifications and came across something VEEEEERY interesting... (emphasis added) *Faces and surfaces can be assigned into named groups with the "g" keyword. This is used to create convenient sub-objects to make it easier to edit and animate 3D models. **Faces can belong to more than one group.*** What implications could this have on Poser model building? When a poly can exist smultaneously in two different groups? There is some other interesting stuff in there, that might crash poser or might be properly read by poser, like 'cstype' and 'surf' -- I don't know if any experimentation has been done with these.