In the current specification, there’s a note stating:

"A block container box can both establish a block formatting context and an inline formatting context simultaneously."

It’s not immediately intuitive how a block container could establish both a block formatting context (BFC) and an inline formatting context (FC) at the same time, as these formatting contexts typically serve different layout functions.

Questions:

1. Could you clarify what is meant by a block container box establishing both a BFC and an inline FC simultaneously?
2. Under what conditions would this occur, and how should it be expected to behave?
3. Are there specific examples that illustrate this behavior?

Thanks in advance.