An EAN-13 barcode is a 13 digit (12 data and 1 check) barcoding standard. The EAN-13 barcode is defined by the standards organization GS1.
The EAN-13 barcodes are used worldwide for marking products often sold at retail point of sale.
The 13 digits in the EAN-13 barcode are grouped as follows:
The less commonly used EAN-8 barcodes are used also for marking retail goods; however, they are usually reserved for smaller items, for example confectionery.
73513537 9780471117094 4006381333931 are valid,
73513536 is invalid.