--- relativity.module.orig	2009-11-11 14:14:13.000000000 +0200
+++ relativity.module	2009-11-11 16:56:19.000000000 +0200
@@ -1085,6 +1085,8 @@ function relativity_nodeapi(&$node, $op,
 
     // remove all relationships involving this node from the database table
     case 'delete':
+      // Let other modules act before before deleting a node.
+      module_invoke_all('relativity', 'delete', $node);
       relativity_delete_relationships($node);
       break;