UMLR — Message arguments for a Signal signature too restrictive

Constraint 4 of Message in section 14.3.18 requires that in case of a Signal signature, the arguments of the message must correspond to the properties of the Signal.

We found this constraint too restrictive. A Signal is a classifier, hence it is possible to create an InstanceSpecification for the Signal. A InstanceSpecification can be referenced by an InstanceValue (ValueSpecification) from within the message argument list.

We suggest to weaken the first sentence of constraint 4 a little from :

In the case when the Message signature is a Signal, the arguments of the Message must correspond to the attributes of the
Signal.

to

In the case when the Message signature is a Signal, the arguments of the Message must correspond to the attributes of the
Signal, or to the Signal itself.