If you try to name another element with a used name, an alert shows in the bottom of the diagram editor. You can let the things as they are and do nothing - just ignore the alert or you can even close it to not disturb you. However, if you added a second instance of an existing object in your project there is an interesting option which this pane offers you - you can link the new element with the existing object. Click on the button with the name of the object and the model will be attached to the new element.
Identification of Existing Name
Tutorials| 19 September 2018 8:06:38 Dusan Rodina - softwareideas.net
You can name several elements in your project with the same name but sometimes it may not be what you want. Software Ideas Modeler warns you if you use one name twice.