UMLR — Issue with Reply message in interactions (UML 2.5 Beta)

There is a clarifying statement for the labels on reply messages that was added in UML 2.5 Beta, which reads:

"The message-name appearing in a reply-message-label is the name property of the Message. If the Message has a signature, this will be the name of the Operation referenced by the signature (which should be the Operation for whose call this is a reply)."

This is more constrained than was the case in UML 2.4 and can lead to some backward compatibility problems. Namely, there is a situation supported in RSA-RTE where the reply message to an Operation call can have a different label than the name of the Operation to which it is a response.

Although there is no OCL constraint that mandates that the label of the reply message has to be the same as the Operation that caused it, the above text can be interpreted as if such a constraint existed. My suggestion is to modify the second sentence in the quoted text above to read:

" If the Message has a signature, this can be the name of the Operation referenced by the signature (which should be the Operation for whose call this is a reply)."

This leaves the clarification in place, but does not prevent the possibility of different labels on the reply message.