Payment service is selectable if <CORE paymentServiceChoice="true">
and the number of payment services to select is greater than one.
Article is selectable if
<CORE articleChoice="true">
and the number of articles to select is greater than one.
<PAYMENTSERVICE articleChoice="true">
and the number of articles to select is greater than one. This requires that there is a current payment service.
Tariff is selectable if <PAYMENTSERVICE tariffChoice="true"> and the number of tariffs to select is greater than one. This requires that there is a current payment service.