Delete

The Delete command removes the current selection from the document.

If you are in a drawing and you delete a symbol that represents a product in your project, only the symbol is deleted from the drawing; Delete, by itself, does not remove the product from the project and the deleted symbol will appear in the Available Symbols Palette.

To delete a product from your project when in a drawing, use Shift+Delete.  This removes the symbol from the drawing, and the product from the project, so any symbols of the same product instance in different drawings will also be deleted.