I admit to being confused. If you make a selection of polygons in the VM and select "name polygon group" from the menu you will create a "g" line in your exported object file; the same line used for Poser groups, and recognized by UVmapper as well. As of Carrara 5,if you take a selection and give it a new material domain name, you create a standard "usemtl" line that also shows up in both Poser and UVmapper as a "material." The only problem I am aware of is a persistent bug in Carrara's VM that will delete those group names (of a Carrara-created or imported mesh), when certain modeling or selection steps are performed.