QR codes
A printed code whose destination you can change afterwards.
Make a code
Give it a name you will recognise later, like "Fridge" or "Wedding table cards", and a destination. The name is only for your own list. It never appears in the code.
Print it
Print it opens a sheet with nothing else on the page. Pick the size in inches, how many to a page, and whether to caption each one. Print at 100 percent with scaling and "fit to page" turned off, or they will not come out the size you chose. Scan one with your phone before you print the run.
Or download it
SVG for anything going to a printer or a sign maker, because it stays sharp at any size. PNG at 600, 1200 or 2400 pixels for everything else.
A batch at once
Paste one name per line, up to fifty. Each line gets its own code, which is the point: separate codes tell you which box, which table or which card is actually being scanned. One code on everything answers none of that. A line can carry its own destination after a vertical bar if that one should go somewhere different.
Change where it goes, whenever
Open the code, type a new destination, save. It takes effect on the next scan. Every destination it has ever had is kept, with who changed it and when, so there is a record.
Sound wave codes
Upload a recording, or record one in the browser. We measure the sound wave from the audio itself and print it alongside the code, so the shape on the card is that recording and no other. Scanning it opens a page that plays it. Anyone who scans it can hear it, with no account and no password, so treat it like something pinned to a noticeboard.
Pausing and removing
Pausing gives anyone who scans it a page explaining the code is paused, rather than an error. Removing is only possible for a code nothing has ever scanned, because a code with scans is already out in the world. Either way the short code is kept forever and is never given to anything else, so an old sticker can never start pointing at a stranger.