always use charset config item
diff --git a/application/config/config.php b/application/config/config.php
index 880393c..a6d10d8 100644
--- a/application/config/config.php
+++ b/application/config/config.php
@@ -79,6 +79,8 @@
 | This determines which character set is used by default in various methods
 | that require a character set to be provided.
 |
+| See http://php.net/htmlspecialchars for a list of supported charsets.
+|
 */
 $config['charset'] = 'UTF-8';