If you are not already familiar with QR Codes, Wikipedia describes them thus:
"QR code (abbreviated from Quick Response Code) is the trademark for a type of matrix barcode (or two-dimensional barcode) first designed for the automotive industry in Japan. A barcode is a machine-readable optical label that contains information about the item to which it is attached. QR code - Wikipedia, the free encyclopedia"
How do these thingies help on an av-installation then?
Well, it's simple, we place how-to-guides, item-specific manuals, etc. on to a website. Then we stick a QR code on to equipment & control panels that point that device directly at the specific page target for that code.