Single line comments look the same as JavaScript comments and must be placed on their own line:
// just some paragraphs
p foo
p bar<!-- just some paragraphs-->
<p>foo</p>
<p>bar</p>Jade also supports unbuffered comments, by simply adding a hyphen
//- will not output within markup
p foo
p bar<p>foo</p>
<p>bar</p>Block Comments
A block comment is legal as well:
body
//
As much text as you want
can go here.<body>
<!--
As much text as you want
can go here.
-->
</body>Conditional Comments
Jade does not have any special syntax for conditional comments. If your line begins with < then it is treated as plain text. So just use normal HTML style conditional comments:
<!--[if IE 8]>
<html lang="en" class="lt-ie9">
<![endif]-->
<!--[if gt IE 8]><!-->
<html lang="en">
<!--<![endif]--><!--[if IE 8]>
<html lang="en" class="lt-ie9">
<![endif]-->
<!--[if gt IE 8]><!-->
<html lang="en">
<!--<![endif]-->