'SL::DB::DeliveryOrder' => sub { $_[0]->donumber },
'SL::DB::Invoice' => sub { $_[0]->invnumber },
'SL::DB::PurchaseInvoice' => sub { $_[0]->invnumber },
'SL::DB::DeliveryOrder' => sub { $_[0]->donumber },
'SL::DB::Invoice' => sub { $_[0]->invnumber },
'SL::DB::PurchaseInvoice' => sub { $_[0]->invnumber },