Groups have a field called "Rail Sim". It is automatically created by 3DC, and if exporting via the Train Simulator Wizard, it is automatically filled in with the group name the first time the Train Simulator Wizard is run.
The reason for this field is to permit a single model to be exported to multiple rail simulators without having to keep two versions of the model. So, there is a "MSTS" group field, and a "Rail Sim" group field. This limits the number of changes required to export to each. I realize that in practice it doesn’t quite work out "perfectly", but it was an attempt to minimize the number of changes required during the development of a new model. You could check the model in both simulators without any changes. Later, you would add "simulator specific" shapes such as shadows, exhaust points (I forget the exact term). This usage is mentioned, but definitely could be better documented: [url:3k2gp74q]http://amabilis.com/forum/viewtopic.php?f=7&t=4005[/url:3k2gp74q]
