This is a sample sentence to test Markdown in the comments of a WordPress blog with Jetpack Markdown enabled for comments.
<h1 id="test">This is a code block</h1>
<head>
<script>alert("Anything goes in here");</script>
<meta>because it just should just be escaped anyway</meta>
</head>
<?php echo "hopefully WordPress doesn't strip anything"; ?>
<span>Even for anon/low-privileged users (non admins)</span>
Hopefully this fenced code block comes out wrapped in <pre> and <code> tags.
Single-backticked <code> should allow anything also, since it escapes, like this <script>alert("hi");</script>