The standalone 'markdown' utility is perfectly happy with an external link inside a <h1>, e.g.:

# Review of [Dwarf Fortress][]
[Dwarf Fortress]:


<h1>Review of <a href="">Dwarf Fortress</a></h1>

but when I try to use this construct in an ikiwiki page, I get

<h1>Review of [Dwarf Fortress][]</h1>

It works fine with h2 and deeper. The square brackets also appear in the output of an inline directive in archive mode, I haven't tried non-archive mode.

I think you were confused by markdown's slightly wacky mix of square brackets and parens. The url in a markdown link goes in parens, not square brackets. For example:


done --Joey

It works here but it definitely does not work on my wiki; but on further experimentation, I believe my problem is being caused by JasonBlevins' h1title plugin.