(31)The operation and supervision of IORPs differ significantly between Member States. In some Member States, supervision can be exercised not only over the IORP itself but also over the entities or companies which are authorised to manage such IORPs. Member States should be able to take such specificity into account as long as all the requirements laid down in this Directive are effectively met. Member States should also be able to allow insurance entities and other financial entities to manage IORPs.