There are a number of places in the Workbench and CFX products where geometric faces and regions of mesh can be grouped together and assigned names. While this provides a large amount of flexibility, it can lead to confusion. It is accepted that the current design is not optimal and will be improved for future releases. This document describes the ‘best practice’ for region definitions for the 11.0 release and is targeted mainly at CFD users of the DesignModeler, Meshing Application and CFX products.