When IkiWiki uses discount to implement mdwn rendering, there is a workaround for https://rt.cpan.org/Ticket/Display.html?id=74016:

$t=~s/<style/<elyts/ig;
my $r=Text::Markdown::Discount::markdown($t);
$r=~s/<elyts/<style/ig;

However, this workaround also applies to indented text or text in backticks: if you write there is a bug involving the `<style>` tag, or use indentation like

you can use this markup:

    <style type="text/css">...</style>

then that gets turned into <elyts in the source before passing through markdown, comes out as &lt;elyts in the output HTML, and is rendered as <elyts by the browser. This makes it quite difficult to talk about HTML stylesheet markup on an IkiWiki instance (I had to use raw HTML in this bug report's source to avoid the bug).

I think the side-effect of the workaround is more damaging than the actual bug being worked around: I've never wanted to write inline style tags in the body of a Markdown page (which isn't even valid HTML) but I have certainly wanted to discuss style markup several times. The first couple of times I saw this happen, I thought it was some sort of misguided anti-cross-site-scripting filter...

--smcv