PUBLIC MARKS with tags QR & ux

like popular 2D barcode "QR code" but invisible.

[…] However, if it is invisible how can people notice that the code is there? Actually, touch-less radio-communication system like NFC has the same problem when you try to use it like QR Code.

The call to action simply isn’t sufficient to overcome people’s lack of interest in and inclination to click on an otherwise opaque code…especially now that there are the first stirrings of a general awareness that QR malware can be used to inject malicious exploit code into one’s device.