When you work with printed documents that contain these barcodes, you can use the barcode information displayed in the document to search for and locate the original copy of the document on an Office SharePoint Server 2007 site. Only when you choose to edit the document and then either save or print it is the barcode inserted into the file as an image. When you upload a file to a document library that has a barcode policy, a barcode is added to the item's properties (metadata) but is not inserted into the file itself.
