Do I have to replace a QR Code if I revise it?

No. To update the information on a QR Code you can revise the course.

Once you create and print out a QR Code you never have to replace it. To update the information on the ving linked to that QR Code just simply revise the ving and then click publish. When you scan the QR Code in the future it will take you to the latest version of that ving.