Number of Digits
Barcodes are allowing our App to find an item very fast in the database and are thus important. Over the years there were barcodes with 8, 9, 10, 11, 12, 13 and 16 digits and all of those can be added to an entry (less than 8 or more than 16 digits will be rejected).
Nowadays the mostly North-American UPC with its 12 digits (like the one above) and the European EAN with 13 digits are the two important barcodes.
In some cases, Brands use one UPC for a number of different items. For example, a standard Hot Wheels case shares the same UPC in which case a search for that UPC will show you all models that were in the case. Another example are items packaged in Blind Boxes. A UPC search will find the blind-boxed item and that item in turn will show all Database Entries that could be it.
Here for example the UPC Search would show this page with all the items that could come in that pack. The user could now just click on the time they wanted to find the value of, add to their collection or to their Wish List.