UMLR — Tags typed by classes/blocks

The UML Superstructure spec states in Subclause 18.3.7 that:

“A Profile can define Classes, DatatTypes, PrimitiveTypes and Enumerations as well as Stereotypes since Profiles imports Constructs. However, these types can only be used as the type of properties in the profile, they cannot be used as types in models the profile is applied to since they apply at the meta-model level, not the model level. It is however possible to define these types in separate packages and import them as needed in both profiles and models in order to use them for both purposes.

Stereotypes can participate in binary associations. The opposite class can be another stereotype, a non-stereotype class that is owned by a profile, or a metaclass of the reference metamodel. For these associations there must be a property owned by the Stereotype to navigate to the opposite class. Where the opposite class is not a stereotype, the opposite property must be owned by the Association itself rather than the other class/metaclass.”

However, the restrictions expressed in this text are not formalized by any constraints. Either OCL should be added to formalize these restrictions, or the restrictions should be removed