The Enumeration "DataClassEnum" seems not to be used within the data model (i.e. there is no attribute using it).
Maybe it's some kind of meta information, but I'm not sure about this.
It should be checked, whether this enumeration is still necessary or if there is some construct or attribute missing, which was intendet to use it.
This enumeration was put into the model to allow filter constructs to be created in a subscription, i.e. a subscriber could indentify which types of data he would like to receive relating to a particular subscription. Of course this would probably be only one element in the subscription filter construct.
As Exchange is not longer part, this class was removed in 3.0.