The User Diagram Type is used as the basis of creating your Meta Model Diagram. In each diagram that you create you need to specify User Definition Types, along with their properties, create User Symbol Types, along with their Properties. These Definition and Symbol types are then assigned to this diagram.
To create a user diagram type
1 Perform one of these actions:
•In the Explorer, right-click the Definitions group, and then select New Definition.
•Click Dictionary > New Definition.
2 Select User Diagram Type, and then specify a name for it.