You can delete connection occurrences in models. You delete connection definitions on the Relationships tab of the Properties bar..
Procedure
You can delete occurrences of connections. The graphical representation of the connection is deleted from the model but the connection itself is retained and still exists, for example, between objects at the definition level. You can see this on the Relationships tab when you select one of the connected objects.
Procedure
Select the connection.
Press Del.
You can delete connections and relationships. The graphical representation of connections will be deleted, as well. If you delete the definitions, the connections and relationships no longer exist.
Procedure
Select an object whose connection to another object you deleted.
Activate the Relationships tab on the Properties bar.
Click the row containing the connection you deleted. If the connection no longer has any occurrences in any model, the Delete button is enabled.
Click the Delete button.
The connection occurrence will be deleted.