QR codes and index cards?

When I write a quote or note on an index card, I try to record some version of a reference. Most often this is just a title, author, and date of the article or book. When I need to revisit the source, I then need to look it up based on what I'd written on the card. This is fine for physical books, but I had an idea today that could make it easier for digital sources.

What if I put a QR code pointing to the source right on the index card?¹

I have a little Niimbot label printer that can print QR codes. I just paste the URL, and it generates the QR code automatically. What I don't love about it is that I have to get out my phone to make the labels, and the app is pretty awful. And trying to run the iOS app on macOS is an exercise in frustration.

Here's my first run at this:

The QR code could contain anything, really. Not only URLs. I could encode a link into an Obsidian vault, or the path to an Org-mode file, etc.

I'm not sure yet if this is a terrible idea or not, but I feel like it's worth a try.