EAN

The European Article Number was introduced in 1977 as an international extension of the American UPC, with one extra digit for a country prefix. EAN-13 encodes thirteen digits: a GS1 prefix pointing to whichever national numbering office issued the range, a company and item number, and a check digit computed with alternating weights of 1 and 3. A Swedish product typically starts with 73.

The name has since changed to GTIN-13 because the scheme went global, but both the code on the milk carton and the one in the till's database are still called EAN in everyday speech. A barcode scanner reads UPC and EAN with the same optics — the latter is just the former with one more field.