UML14 — Interface must also have features

Summary: Page 16 If Classifiers have features (e.g. attributes and methods) then an
Interface must also have features since it is a kind of Classifier. Yet,
on page 24, it is stated that an Interface has operations only; on page 37
Notation document it clearly states Interface "lacks attributes". If this is
done by an OCL constraint, then we have a negation of properties of the
subtype which Brachman points out to be dangerous.

Considered and declined.