Presentation copy
You can create copies of objects. When copying an object, you can decide whether you wish to create a new object (a definition copy) or a new object symbol for an existing object (an occurrence copy).
It is helpful to create a copy of the object symbol for an existing object - that is, only a copy of the presentation of an object - if exactly the same object is needed at various positions in a diagram or in different diagrams.
For example, if you rename the object Class 1 to Class A, you need to do this for ONE of the presentations only: All other presentations are simultaneously renamed to Class A in the same diagram and in all other diagrams.