MDG stereotype setting to prevent creating Instances ?

[Guillaume]

Hello,
I have an MDG with stereotyped classes and activities. I would like to prevent the option for the users to create an instance of these elements (object or action) when using the drag/drop from the diagram.
I only found the _instanceMode attribute to define if an instance is an object or property.

[qwerty]

I would guess you need an add-in to undo that creation.

q.