Duplicating a symbol lets you use an existing symbol as a starting point for creating a symbol.
To create versions of the symbol with different appearances, also use instances.
Duplicate a symbol using the Library
panel
Select a symbol in the Library
panel and do one of the following:
Right-click (Windows) or Control-click (Macintosh), and select Duplicate from the context menu.
Select Duplicate from the Library Panel menu.
Duplicate a symbol by selecting
an instance