Be careful with boolean defines and assuming a check is done for a specific value by defined such as
<?php
define('DEBUG', false);
if(defined('DEBUG')){
echo 'Not really debugging mode';
}
?>
You want to also check the constant as in
<?php
define('DEBUG', true);
if(defined('DEBUG') && DEBUG){
echo 'Really this is debugging mode';
}
?>
All defined is doing is verifying the constant exists not it's value.