Summary
The name of a Classifier’s Attributes and Roles must be unique in the Classifier and its inherited Classifiers.
Details
The Attributes and AssociationEnds of a Classifier must have a unique name in that Classifier. Furthermore, since when inheriting from a Classifier, some of its properties are inherited as well, the name must be unique in the Classifier, but also in all its parents.
Tips
If you have several Attributes or AssociationEnds with the same name in a Classifier or its parents, you must rename them so they each have a unique name.