Donor tissue that is completely suitable and in respect of which there is no shortage is immediately delivered by ETB-BISLIFE. Donor tissue that is in short supply and therefore scarce, for example typed corneas and some types and dimensions of heart valve, is officially classified in the Netherlands as ‘subject to allocation’. This tissue is allocated by the NTS to institutions using allocation rules that are based on, amongst other factors, medical urgency, patient and tissue-specific criteria, and minimum stocks to be maintained.