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From the looks of the screenshot embedded above, there are two types of QR codes: a personal barcode or a “status QR barcode”. This also seems to appear on Facebook Fan Pages.
Judging from the tweets about this
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We’re trying to get more information and will update accordingly.
Update – Facebook gave us the boilerplate response:
“We’re always testing various features on the site, but we have nothing more to share at this time.”In case you’re not familiar with QR codes: QR is short for Quick Response (because they can be read quickly by a mobile phone through its camera). They are used to take a piece of information from a transitory media and put it in to your cell phone – this can be links, videos, text, photos and more.
QR codes are generally more useful than a standard barcode is that they can store much more data. The other key feature of QR Codes is that instead of requiring a scanner to ‘read’ them, most modern mobile phones can convert them and there are applications out there for smartphone that don’t support native QR code scanning.
Imagine wearing the link to your Facebook profile on your t-shirt – this is what that would look like when converted to a QR code:
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(Thanks to Marco Schierhorn
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source : http://techcrunch.com/2010/03/16/facebook-qr-code/