This is a response to a rejected edit where I wanted to add a bar code to Space Quest IV: Roger Wilco and The Time Rippers. This is the message from the admin:
Can you verify this information? When verifying this information on my own, I can only find 10-digit barcode sequences. - dhaabi https://www.ebay.com/itm/165492785207 / https://www.ebay.com/itm/155151020709 / https://www.ebay.com/itm/185693697693
So it seems that the human readable part of the barcode is only 10 digits, but if you scan it with a barcode reader, the full number is 12 digits. I have the same barcode as the eBay listing in the second link above (if you compare it with the first link it seems the slight difference in UPC depends on whether you have 5.25" floppies or 3.5" floppies).
Here is the image of my barcode, with the readout from my phone:
https://imgur.com/a/ACIpOQRIt's basically the same 10 digit number, padded with the 0 at the front and 6 at the end.
I believe those numbers are usually printed on UPC codes separately from the 10 digit part, but for some reason, they're not printed on this particular label, but a UPC reader will pick them up.
I did one more check, on the MobyGames entry.
https://www.mobygames.com/game/space-quest-iv-roger-wilco-and-the-time-rippers/release-info They don't have complete UPC codes there either, but they've formatted their 12-digit codes in a way that makes it more clear where the 10 digit part is where the start/end numbers are. I hope that helps.