Note: There is a newer version of this specification see VEC 2.0.2
A TopologyZoneSpecification is a container to define TopologyZones. A TopologyZone is a way to define areas on that share a set of properties (e.g. environmental influence).
To define the TopologyZone unambiguously an assignment of the topology elements to their zones is necessary. TopologyNodes are only connecting points for TopologySegments or for the placement of components and do not have any own extent in space. Therefore, ZoneAssignments are only possible for TopologySegments.
For more details, see the description of the relevant classes.