UPC

The Universal Product Code was drawn up by George Laurer at IBM and adopted in 1973 as the industry standard for American retail. Its UPC-A variant encodes twelve digits in the pattern of wide and narrow bars: a prefix for the maker, an item number, and a check digit. On 26 June 1974 the first live pack — a stick of Wrigley's gum — was drawn past a barcode scanner in Troy, Ohio.

The code says nothing about the price; the till looks it up in a database by the number, which was the whole revolution — prices could change without re-tagging the goods. UPC is now administered by GS1 and is, in practice, the special case of EAN where the thirteenth digit is a zero.