I missed that earlier, thanks to the Techno / Marketer I found it now.

The MMA’s Mobile Advertising Guidelines (PDF) provides the formats, guidelines and best practices to implementing mobile advertising initiatives. All parties involved in active mobile advertising programs should be familiar and compliant with Mobile Advertising Guidelines and their practical implementation.

The Mobile Advertising Guidelines includes the following sections:

• Mobile web (WAP) Banner Guidelines
  
  • Mobile web advertising overview
  • Mobile web (WAP) advertising units
  • Advertising examples
  • Technical specifications
  • Mobile web response mechanisms overview
• Content Guidelines
• Technical Requirements for Mobile Advertisers
• Nomenclature (Glossary)
• Who We Are

In September MobileMonday reported that China Mobile offers train e-tickets with QR-Codes. I checked CTTL for an update, but didn't find anything. Does anybody know if they already started?

China Mobile plans to test a train ticketing system using its bar code e-commerce service QRcode in Beijing in October, reports National Business Daily.
With the correct handset QRcode, users can get on trains without having paper tickets.

I suppose it is not so much the direct code scanning which plays a major role but rather receiving a WAP-Push link via SMS to get a QR Code ticket on the device.