Are there provisions to control items that are not listed on the control lists?

Yes. The 2004 NSG Plenary (Göteborg) adopted a mechanism in the NSG Part 2 Guidelines that NSG participants should ensure that their national legislation requires an authorisation for the transfer of items not listed in the Dual-Use Annex if the items in question are or may be intended, in their entirety or in part, for use in connection with a “nuclear explosive activity”. NSG Participants implement such an authorisation requirement in accordance with their domestic licensing practices and are encouraged to share information on “catch-all” denials.