1. In a computer controlled scanning and printing system, a method of providing an updated version of a printed document comprising: storing data for generating an original version of a printed document including: a two-dimensional barcode having: data identifying said original version of said document; and a portion of said data for generating said original version of said document; enabling the updating of said stored data wherein a later version of said printed document may be generated including a new barcode for identifying and generating said later version; scanning the barcode of a version of said document to determine if the scanned barcode identifies the later version of the document; and generating and printing the later version of said document if the scanned barcode does not identify the later version.