Index: t3lib/class.t3lib_div.php
===================================================================
--- t3lib/class.t3lib_div.php	(revision 3557)
+++ t3lib/class.t3lib_div.php	(working copy)
@@ -3019,6 +3019,7 @@
 	 * @internal
 	 */
 	public static function debug_ordvalue($string,$characters=100)	{
+		if ($GLOBALS['TYPO3_CONF_VARS']['SYS']['dontShowDebugOutput']) return '';
 		if(strlen($string) < $characters)	$characters = strlen($string);
 		for ($i=0; $i<$characters; $i++)	{
 			$valuestring.=' '.ord(substr($string,$i,1));
@@ -3102,7 +3103,8 @@
 	 * @return	void
 	 */
 	public static function debug($var='',$brOrHeader=0)	{
-			// buffer the output of debug if no buffering started before
+		if ($GLOBALS['TYPO3_CONF_VARS']['SYS']['dontShowDebugOutput']) return '';
+		// buffer the output of debug if no buffering started before
 		if (ob_get_level()==0) {
 			ob_start();
 		}
@@ -3138,6 +3140,7 @@
 	 * @return	string
 	 */
 	public static function debug_trail()	{
+		if ($GLOBALS['TYPO3_CONF_VARS']['SYS']['dontShowDebugOutput']) return '';
 		$trail = debug_backtrace();
 		$trail = array_reverse($trail);
 		array_pop($trail);
@@ -3159,6 +3162,7 @@
 	 * @return	void		Outputs to browser.
 	 */
 	public static function debugRows($rows,$header='',$returnHTML=FALSE)	{
+		if ($GLOBALS['TYPO3_CONF_VARS']['SYS']['dontShowDebugOutput']) return '';
 		if (is_array($rows))	{
 			reset($rows);
 			$firstEl = current($rows);
 
Index: t3lib/config_default.php
===================================================================
--- t3lib/config_default.php	(revision 3557)
+++ t3lib/config_default.php	(working copy)
@@ -58,6 +58,7 @@
 		'recursiveDomainSearch' => 0,			// Boolean. If set, the search for domain records will be done recursively by stripping parts of the host name off until a matching domain record is found.
 		'devIPmask' => '127.0.0.1,::1',			// Defines a list of IP addresses which will allow development-output to display. The debug() function will use this as a filter. See the function t3lib_div::cmpIP() for details on syntax. Setting this to blank value will deny all. Setting to "*" will allow all.
 		'sqlDebug' => 0,						// Boolean. If set, then database queries that fails are outputted in browser. For development.
+		'dontShowDebugOutput' => 0,				// Boolean. If set, then then no output of the debug functions will be outputted in browser. For making sure no forgetten t3lib_div::debug will output debug live.
 		'enable_DLOG' => FALSE,					// Whether the developer log is enabled. See constant "TYPO3_DLOG"
 		'ddmmyy' => 'd-m-y',					// Format of Date-Month-Year - see PHP-function date()
 		'hhmm' => 'H:i',						// Format of Hours-Minutes - see PHP-function date()