Non-inline mark

MarkSpec.toDOM() accepts an inline: boolean argument. According to the documentation quoted below, it’s true in “typical” cases:

marks does the same for mark names, but also gets an argument that tells it whether the mark’s content is block or inline content (for typical use, it’ll always be inline).

I would like to better understand the purpose of this argument, specifically the “non-typical” cases where inline would be false.

I have looked at the original Git commit that added this argument, but I still do not understand. Is inline can ever be false at all?

It’s possible to allow marks on block nodes via the marks setting in their parent nodes.