diff --git a/wp-admin/includes/plugin.php b/wp-admin/includes/plugin.php
index ae75f2dbde..7e99a07127 100644
--- a/wp-admin/includes/plugin.php
+++ b/wp-admin/includes/plugin.php
@@ -990,7 +990,8 @@ function user_can_access_admin_page() {
  *
  * @since 2.7.0
  *
- * @param string $option_group A settings group name.  Can be anything.
+ * @param string $option_group A settings group name.  Should correspond to a whitelisted option key name.
+ * 	Default whitelisted option key names include "general," "discussion," and "reading," among others. 
  * @param string $option_name The name of an option to sanitize and save.
  * @param unknown_type $sanitize_callback A callback function that sanitizes the option's value.
  * @return unknown