QRs are a lot more complex than that, though. It’s not a symbol mapping, it’s an encoding of a binary string, which then pieces of map to characters. And even if they do figure out how to decode them, they’ll just get the urls, which won’t mean anything without understanding the internet. True. It probably would take them decades since it’s complicated. But they probably would associate patterns in the QR code to urls and text that come up a lot and eventually figure out how to decode QR codes. It would be funny that they would get useless url that provides next to no context. It also interesting that the ink will probably only last few generations and well after the lives of anyone that cared about the deceased. There are qr codes made from solid material. Like the material is black and the negative space is White