The Clone command lets you quickly create a new design diagram or element with the same content as the existing one. An element that can be cut, copied and pasted can also be cloned by using the Clone command. Cloning is basically a one-step copy-and-paste.
To clone an element or diagram:
In the UML Explorer, UML Navigator or Diagram view, select the diagram or element to be cloned.
Right click on the element and select Clone from the context menu.
The new cloned diagram appears in UML Navigator and UML Explorer view, and it opens in the Diagram View.
NB: It is not possible to clone default or package diagrams.