diff --git a/code/sitefeatures/SSAkismet.php b/code/sitefeatures/SSAkismet.php
index 2bf0d8fe..60da63ac 100644
--- a/code/sitefeatures/SSAkismet.php
+++ b/code/sitefeatures/SSAkismet.php
@@ -1,5 +1,21 @@
 <?php
 /**
+ * The SSAkismet class provides spam detection for comments using http://akismet.com/. 
+ * In order to use it, you must get an API key, which you can get free for non-commercial use by signing 
+ * up for a http://www.wordpress.com account. Commercial keys can be bought at http://akismet.com/commercial/.
+ * 
+ * To enable spam detection, set your API key in _config.php.  
+ * The following lines should be added to **mysite/_config.php** 
+ * (or to the _config.php in another folder if you're not using mysite). 
+ * 
+ * <code>
+ * SSAkismet::setAPIKey('<your-key>');
+ * </code>
+ * 
+ * You can then view spam for a page by appending <i>?showspam=1</i> to the url, or use the {@link CommentAdmin} in the CMS.
+ * 
+ * @see http://demo.silverstripe.com/blog Demo of SSAkismet in action
+ * 
  * @package cms
  * @subpackage comments
  */