I'm sure everyone knows QR codes - those little square boxes with the black and white squares that can only be decoded with a smartphone and the appropriate software.
But can this also be done by hand? In other words, without technical aids? And surprisingly, according to a recent article in the IT news magazine Golem.de, this is possible via reports a net findwhich I found quite interesting and would like to share here so that people who are interested in the topic can link to it. Since the topic is quite complex, and a developer has already done this very well, I have the Original page with the instructions linked.
Continue here
Web Archive Link / Fallback Archive
Here is a short video that shows how a QR code is structured:
English 
German 
French 
Czech