=item feepart - key of the fee definition (L<FS::part_fee>).
+=item nextbill - 'Y' if the fee should be charged on the customer's next
+bill, rather than causing a bill to be produced immediately.
+
=back
=head1 METHODS
|| $self->ut_foreign_key('eventnum', 'cust_event', 'eventnum')
|| $self->ut_foreign_keyn('billpkgnum', 'cust_bill_pkg', 'billpkgnum')
|| $self->ut_foreign_key('feepart', 'part_fee', 'feepart')
+ || $self->ut_flag('nextbill')
;
return $error if $error;