Call out boxes??

Hi everyone

I hope to start looking at the design method "Use white space and call out boxes". I am trying to find out exactly what we mean by call out boxes. Are we referring to highlighted boxes as W3C uses on our GitHub boxes or are we referring to Card UI components<https://www.nngroup.com/articles/cards-component/> which are now ubiquitous (or both)?

I am raising the Card UI topic as they come up a lot in my day-to-day testing role where they can be implemented well or badly for COGA and other accessibility/AT groups. So I was hoping our design guide would include them.

Many thanks

Abi