UMLR — UML2 Super / 14.3.13 Interaction

Chapter 14.3.13 states on p. 526 that "Interactions are units of behavior of an enclosing Classifier. Interactions focus on the passing of information with
Messages between the ConnectableElements of the Classifier." From chapter 9.3.13, it is obvious that only StructuredClassifiers can have such ConnectableElements. Additionally, chapter 13.3.2 states that the context of a Behavior is a BehavioredClassifier. When looking at the Classifier Hierarchy in Appendix F of the Spec, you will find a single Element which is a BehavioredClassifier, but not a StructuredClassifier: the UseCase.
This is where the problems start.
A UseCase is not allowed to have properties at all, but may be the owner of an Interaction. Consequently, with the current version of the Spec, an Interaction owned by a UseCase may never have any Lifeline at all!

Proposed Resolution:
Redefine the Association Behavior::context: BehavioredClassifier[0..1] to Interaction::context: StructuredClassifier, replace all occurrences of 'BehavioredClassifier' in the description by 'StructuredClassifier'
It should still be possible that a UseCase is the owner of the Interation, but the determination of the Interaction's context would be much clearer.