diff --git a/inc/DifferenceEngine.php b/inc/DifferenceEngine.php
index 783d6bea5a3b4b86efe438c8c88aa661ced86420..07df7a4bef1a7226193971af154d7da7f70a4759 100644
--- a/inc/DifferenceEngine.php
+++ b/inc/DifferenceEngine.php
@@ -817,7 +817,16 @@ class DiffFormatter {
         $this->_added($closing);
     }
 
-    function _escape($str){
+    /**
+     * Escape string
+     * 
+     * Override this method within other formatters if escaping required.
+     * Base class requires $str to be returned WITHOUT escaping.
+     * 
+     * @param $str string Text string to escape
+     * @return string The escaped string.
+     */
+     function _escape($str){
         return $str;
     }
 }