Horizontal rules are useful for breaking up sections that don't require a header. It would also bring fandoc closer to markdown (for better compatibility) as markdown allows horizontal rules.

There shouldn't be any clash with H4 headers, as headers require title text and horizontal rules should have clear lines above (and below?).

H4 title
--------   <-- H4 title


----       <-- Horizontal rule

Yeah I've wanted that a few times -- would require a leading/trailing space most likely -- but seems ok.

This is now available in tip

changeset

Nice!