ARIA 1.1. Layout Grid as interactive list container pattern

Hi Matt, Bryan,

Can you point me to the exact locations in

https://rawgit.com/w3c/aria/master/aria/aria.html

and

http://w3c.github.io/aria/practices/aria-practices.htm

where the concept of a layout grid is explained that should stand in as a pattern for a focusable container (grid cells) with actionable non-presentational content (grid cell content)?

We have talked about this in last ARIA telco and I'm not able to spot it although I want to follow your recommendation to read it.

Thanks + Best Regards
Stefan