diff --git a/application/helpers/asset_helper.php b/application/helpers/asset_helper.php
index 30544248..9c135a66 100644
--- a/application/helpers/asset_helper.php
+++ b/application/helpers/asset_helper.php
@@ -24,8 +24,6 @@
  */
 function asset_url($uri = '', $protocol = NULL)
 {
-    $CI =& get_instance();
-
     $debug = config('debug');
 
     $cache_busting_token = ! $debug ? '?' . config('cache_busting_token') : '';
diff --git a/application/helpers/custom_exceptions_helper.php b/application/helpers/custom_exceptions_helper.php
index 64865197..0bc56f84 100644
--- a/application/helpers/custom_exceptions_helper.php
+++ b/application/helpers/custom_exceptions_helper.php
@@ -14,13 +14,13 @@
 /**
  * Print an exception to an HTML text.
  *
- * This method is used to display exceptions in a way that is useful and easy
- * for the user to see. It uses the Bootstrap CSS accordion markup to display
- * the message and when the user clicks on it the exception trace will be revealed.
- * We display only one exceptions at a time because the user needs to be able
- * to display the details of each exception seperately. (In contrast with js).
+ * This method is used to display exceptions in a way that is useful and easy for the user to see. It uses the
+ * Bootstrap CSS accordion markup to display the message and when the user clicks on it the exception trace will be
+ * revealed. We display only one exceptions at a time because the user needs to be able to display the details of each
+ * exception separately.
  *
  * @param Exception $exception The exception to be displayed.
+ *
  * @return string Returns the html markup of the exception.
  */
 function exceptionToHtml($exception)
@@ -30,8 +30,7 @@ function exceptionToHtml($exception)
             <div class="accordion-group">
                 <div class="accordion-heading">
                     <a class="accordion-toggle" data-toggle="collapse"
-                            data-parent="#error-accordion" href="#error-technical">' .
-        $exception->getMessage() . '
+                            data-parent="#error-accordion" href="#error-technical">' . $exception->getMessage() . '
                     </a>
                 </div>
                 <div id="error-technical" class="accordion-body collapse">
diff --git a/application/helpers/data_validation_helper.php b/application/helpers/data_validation_helper.php
index 1d73e3e6..b2756642 100644
--- a/application/helpers/data_validation_helper.php
+++ b/application/helpers/data_validation_helper.php
@@ -12,10 +12,10 @@
  * ---------------------------------------------------------------------------- */
 
 /**
- * Check if a string date is valid for insertion or update
- * to the database.
+ * Check if a string date is valid for insertion or update to the database.
  *
  * @param string $datetime The given date.
+ *
  * @return bool Returns the validation result.
  *
  * @link http://stackoverflow.com/a/8105844/1718162 [SOURCE]
@@ -23,6 +23,6 @@
 function validate_mysql_datetime($datetime)
 {
     $dt = DateTime::createFromFormat('Y-m-d H:i:s', $datetime);
-    
+
     return $dt ? TRUE : FALSE;
 }
diff --git a/application/helpers/render_helper.php b/application/helpers/render_helper.php
index f569180a..ad55aa82 100644
--- a/application/helpers/render_helper.php
+++ b/application/helpers/render_helper.php
@@ -15,7 +15,8 @@
  * Render the HTML output of a timezone dropdown element.
  *
  * @param string $attributes HTML element attributes of the dropdown.
- * @return false|string
+ *
+ * @return string
  */
 function render_timezone_dropdown($attributes = '')
 {