Conclusions: Defining the operational rules for INN prescribing for and with different stakeholders was a difficult yet feasible assignment. The INN prescribing project resulted into explicit operational rules and a reference database. The Belgian experience may provide important information for other countries planning to operationalize or refine electronic INN prescribing. It can also be used for a thorough evaluation of the impact of the new concept of INN prescribing on daily practice and on medical education. (Source: International Journal of Medical Informatics).