Thank you so much for posting the missing pieces.
I have been doing data merge QR codes in the past but with plugins and workarounds so I was very excited to see this as an new feature. But as with all data driven or "code" based features, the programmers assume you have a deep knowledge of code/syntax and forget that they are working with designers. They leave out several pieces of info that they think are common knowledge.
I use the same wikipedia page for QR syntax reference, very helpful!!
Kevin