Which classification marking is used for NATO SECRET information?

The classification marking used for NATO SECRET information is represented as "//NS." This designation aligns with the procedures and standards established by NATO for protecting classified information. NATO SECRET is a level of classification that indicates information which, if disclosed, could be expected to cause serious damage to NATO's interests.

In the context of NATO’s information security policy, specific markings denote various classification levels to ensure that personnel handling such information can accurately identify its sensitivity and the corresponding handling requirements. The "//NS" marking is a clear signal to individuals trained in NATO protocols that the information requires a specific level of protection and should only be shared with individuals possessing the appropriate security clearance.