Netherlands Works Councils Act (WOR) 20: Art. 20 Impose confidentiality on the council only by stating in advance what is covered and for how long

Council and committee members, consulted experts and secretaries must keep secret business and trade secrets they learn in that capacity and matters on which the entrepreneur (or the council) has imposed confidentiality. When the entrepreneur imposes confidentiality he announces the intention as far as possible before the matter is dealt with, and states which written or oral information is covered, how long the duty lasts and whether there are persons towards whom it need not be observed; a refusal to allow a member to consult an outsider under confidentiality must be reasoned (20(5)). The council may ask the cantonal court to lift confidentiality that could not reasonably have been imposed (20(7)).