diff --git a/doc/markdown.mdwn b/doc/markdown.mdwn
index 0ca9576d5..3684fe5c1 100644
--- a/doc/markdown.mdwn
+++ b/doc/markdown.mdwn
@@ -5,5 +5,4 @@ email messages. It is the markup language used by this wiki.
 For documentation about the markdown syntax, see [[HelpOnFormatting]] and
 [Markdown: syntax](http://daringfireball.net/projects/markdown/syntax).
 
-Note that [[WikiLink]]s are not part of the markdown syntax, and are the
-only bit of markup that this wiki handles internally.
+Note that [[WikiLink]]s and [[PostProcessorDirective]]s are not part of the markdown syntax, and are the only bit of markup that this wiki handles internally.