GHSA-mc3g-88wq-6f4x talks about "marker rows".
While I do see markers mentioned in the referenced code, searching for "markdown table marker row"
in general basically only hits on this advisory. Could you briefly explain what a "marker row" is?
I understand header row, delimiter row, and data row, but what is a marker row?

I am trying to work out a test to check that the mentioned CVE is indeed fixed, but since I don't understand "marker row", I am not sure what to test exactly, thanks.