During the submission or the workflow the system check the item signatures to find potential duplicates. If any potential duplicate is found a popup is shown to the submitter asking to confirm or reject the finding
The submitter decision is recorded and available to the administrator and librarians during the workflow (See also The administrative UI )
If the workflow is enabled the librarian will see the same alert popup. If the submitter has declared that the match was a fake they can confirm or flag the record as necessary to merge so to have it highlighted in the administrative UI.