

Anatomy of a QR Code - J3L2404
http://www.qrme.co.uk/qr-code-resources/understanding-a-qr-code.html

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zandorg
The problem I had with QR codes is it doesn't say "QR Code" anywhere on it! I
looked at the QR codes on my bathroom detergent bottles, and didn't know it
was that until I read about QR codes in a newspaper.

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jonknee
A UPC-A barcode doesn't label itself as such either. They look bizarre until
you see what happens with a barcode scanner and then they're easily
identifiable and quite normal. It's no different with QR codes.

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orenmazor
heh. I have a moleskin I draw QR codes in by hand when I need to zone out.

so far, none are readable with my phone. maybe graph paper next time.

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bigtech
I get the data structure, but is there some metadata? How does it know the
contents are, say, an URL, or a vcard?

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smackfu
I think it is just: store bytes and let the reader decide how to deal with
them. Starts with "http", it's a URL. Starts with "BEGIN:VCARD", it's a vcard.
Primitive but it works well enough I guess.

