Information capacity and versions of QR Code

There are 40 versions of the QR Code. Details of these are explained here.

iQR Code

QR code - Wikipedia

How QR Codes Work and Their History

On Double-Sided QR-Codes

PDF) The Application of QR Codes And WIFI Technology in the

The capacity of the confidential stream under different QR code versions.

What is a QR Code?

Can a QR code be an image? - Quora

QRazyBox - Help Page