Index: trunk/core/units/custom_fields/custom_fields_config.php
===================================================================
diff -u -N -r4029 -r4330
--- trunk/core/units/custom_fields/custom_fields_config.php	(.../custom_fields_config.php)	(revision 4029)
+++ trunk/core/units/custom_fields/custom_fields_config.php	(.../custom_fields_config.php)	(revision 4330)
@@ -83,6 +83,7 @@
 										            'ValueList' => Array('type' => 'string','default' => ''),
 										            'DisplayOrder' => Array('type' => 'int','not_null' => '1','default' => '0'),
 										            'OnGeneralTab' => Array('type' => 'int','not_null' => '1','default' => '0'),
+										            'IsSystem' => Array('type' => 'int', 'not_null' => '1', 'default' => '0'),
 											),
 					'VirtualFields'	=> 	Array(
 													'Value'	=>	Array('type' => 'string', 'default' => ''),