I have seen that in some of the SE entries, such as Missing number, treated as zero on section using package titlesec, that the start of a comment overlaps the end of the question.
How could I do this with LaTeX? Consider two paragraphs in the source where in the typeset output the words in the bottom half of the first paragraph are overlaid by the words in the top half of the second paragraph. I'm not sure I would ever want to do this, but if I did, how could I?
How does SE manage to do it? Is it controlled by SE or is it something done by the respondents?