SDMN — Semantics of Connector class

SharedDataModel has property connector[0..*]: Connector

Is the meaning of the class Connector connector types or instances? The documentation of this property is:

This is a list of the Connectors (Composition, Containment, Reference, and Data Association) that are included in the SharedDataModel.

It is not clear whether this is a list of possible Connector types or a list of actual Connector instances. The type Connector has outgoing relationships targetRef and sourceRef, which suggests an instance level concept; I am not sure how this relates to the idea of Connector as a specialised ElementRelationshipType, which appears to be as a definer of relationship types.

Proposed change:

improve documentation of SharedDataModel.connectors to clarify whether it is a list of connector types used within a model, or connector instances.

Update Connector model and specification section

The Connector class should be updated so that it is a subclass of SCEElement instead of ElementRelationshipType.
Remove the constraints (for ElementRelationshipKind) from the four concrete types of Connectors.
Update the Text as needed.