For your eyes only

What’s in a security classification?

NATO works with sensitive information and limits access to individuals with proper security clearances. Unintended or malicious disclosure could cause damage to NATO’s forces, its members or its mission. Therefore, classified information is protected through a series of security procedures based on its markings.

There are three possible classification categories, Non-Classified, Unclassified and Classified. Non-Classified documents are either unmarked, or marked as Public, Non-Classified, or Releasable for internet transmission. In the case of Publicly Disclosed material, this is stamped on the left hand side of the document.

Material marked NATO UNCLASSIFIED is managed and owned by NATO. The first part, ‘NATO,’ refers to the ownership, while ‘UNCLASSIFIED’ is the level of security marking. Unclassified information should only be used for official purposes, and not be released without authorization nor published online. This marking can seem somewhat contradictory to those outside the organization. NATO UNCLASSIFIED can be understood as similar to copyright protection, where the information constitutes NATO’s intellectual property.

Beyond that, four levels of security classification exist: NATO RESTRICTED, NATO CONFIDENTIAL, NATO SECRET, AND COSMIC TOP SECRET.

In general, the most common security marking at NATO is Unclassified and Restricted. Confidential and Secret are less common, and the least common marking is Cosmic Top Secret. In times of tension, or during summits and ministerials, the percentage of NATO CONFIDENTIAL and NATO SECRET documents goes up. During calmer periods, like the summer holidays, or while a budget is being passed, the volume of classified information decreases.