@@4.91. Early involvement of interested parties should be ensured as part of the process of building confidence in the safety of the disposal facility. A range of different models for interested party involvement has been applied in different States, and extensive research has been conducted on the methods of engaging interested parties in both national and international research programmes. A key consideration is that interested party involvement should take place within an open and transparent framework for consultation, with clearly defined rules of procedure. The process for involvement of interested parties should be set out in the safety case.