<Li> NATO SECRET (NS) </Li> <Li> NATO CONFIDENTIAL (NC) </Li> <Li> NATO RESTRICTED (NR) </Li> <P> A special case exists with regard to NATO UNCLASSIFIED (NU) information . Documents with this marking are NATO property (copyright) and must not be made public without NATO permission . </P>

Which of the following is not a category of confidentiality protection at the state level