The dictionary content type corresponds to sets of CAM rules - date = setDateMask() and so on. These need to be configurable by dictionary within a dictionary collection. Add the capability to provide type to content rule matching to collections. If none is provided use NIEM specific defaults.
So when user does a drag and drop into a structure - the appropriate rules are added automatically based on the content type of each item in the dictionary. If no rule found - do nothing - and assume simple string type (the default in CAM anyway).