Once a .Z2G file has been set and processed data such as the zone-to-group mappings, the names of the groups etc. are included within the header records of any output .UFM files such that any future applications of those .UFM files will allow immediate access to the zone-to-group information which in turn allows certain operations such as aggregation to groups to be carried out automatically. See, for example, MXZ2G, section 10.20.22.