diff --git a/user_guide/libraries/output.html b/user_guide/libraries/output.html
index ab8f1d6..25ec521 100644
--- a/user_guide/libraries/output.html
+++ b/user_guide/libraries/output.html
@@ -78,6 +78,21 @@
 For example, if you build a page in one of your controller functions, don't set the output until the end.</p>
 
 
+<h2>$this->output->set_content_type();</h2>
+
+<p>Permits you to set the mime-type of your page so you can serve JSON data, JPEG's, XML, etc easily.</p>
+
+<code>$this->output<br/>
+&nbsp;&nbsp;&nbsp;&nbsp;->set_content_type('application/json')<br/>
+&nbsp;&nbsp;&nbsp;&nbsp;->set_output(json_encode(array('foo' => 'bar')));<br/>
+<br/>
+$this->output<br/>
+&nbsp;&nbsp;&nbsp;&nbsp;->set_content_type('jpeg') // You could also use ".jpeg" which will have the full stop removed before looking in config/mimes.php<br/>
+&nbsp;&nbsp;&nbsp;&nbsp;->set_output(file_get_contents('files/something.jpg'));</code>
+
+<p><strong>Important:</strong> Make sure any non-mime string you pass to this method exists in config/mimes.php or it will have no effect.</p>
+
+
 <h2>$this->output->get_output();</h2>
 
 <p>Permits you to manually retrieve any output that has been sent for storage in the output class.  Usage example:</p>