Duplicate Barcodes
What is this?
Barcodes should serve as unique identifiers for their resources. Some systems enforce this requirement by not allowing a barcode to be added to an item if it is already in the system, or by adding a suffix to make it unique.
Why is this trouble?
If the barcode on an item is in multiple records in the system, this may cause strange behavior when the item circulates.
If duplicate barcodes in the system have had suffixes added to make them unique, circulation processes may not work correctly for the original barcode.
Exceptions
There may be exceptions depending on local practices.
How to Find
If you are in Alma, there is an analysis to search for this issue in the "Looking for Trouble" folder. Go to the "Barcodes" folder and look for the "Duplicate Barcodes" analysis. This looks for the pattern of long barcodes with hyphens, which is evidence that they may have been made unique in the system. Alma does not allow saving item records with barcodes that match others in the system.