Article 4 Protection of classified information
1. EUCI shall be protected in accordance with this Decision.
2. The holder of any item of EUCI shall be responsible for protecting it in accordance with this Decision.
3. Where Member States introduce classified information bearing a national security classification marking into the structures or networks of the European Union, the Council and the GSC shall protect that information in accordance with the requirements applicable to EUCI at the equivalent level as set out in the table of equivalence of security classifications contained in Appendix B.
4. Large quantities or a compilation of EUCI may warrant a level of protection corresponding to a higher classification.