The Discogs internal search engine has been very good about bringing up correct release pages when you search for barcodes, even if there are formatting differences (spaces, dashes, leading zeroes) versus how they are entered in the BAOI fields. External search engines like Google are not so smart; you often have to search for the exact string that was entered, or there is no match.
Certain s who want to search for scanned 13-digit EAN codes are tempted to try to normalize the barcode data on the release pages to be pure 13-digit EANs, partly out of ignorance, and partly so that Google will return better results. Example of the drama that ensues: https://www.discogs.sie.com/forum/thread/772696
This is a problem because it encourages preference editing (by adding leading zeroes to correctly scanned 12-digit UPC-A barcodes), or falsifying data (by using human-readable text to generate fake "scanned" EANs), or sowing confusion (by adding "EAN" descriptions on releases which actually have UPC-A barcodes).
A possible solution would be to generate a shadow EAN, exactly 13 digits always, and actually put it somewhere in the release data. The shadow EAN could be appended to the HTML page title. Or, it could be hidden in a title/tooltip field on the BAOI fields, but this might not work as well and could hurt SEO, as Google might see it as an attempt to hide text.
