For Official Use Only


For Official Use Only is an information security designation used by some governments.

United States

Among U.S. government information, FOUO is primarily used by the U.S. Department of Defense as a handling instruction for Controlled Unclassified Information which may be exempt from release under exemptions two through nine of the Freedom of Information Act. It is one of the various sub-categorizations for strictly unclassified information which, on 24 February 2012, was officially consolidated as CUI. Other departments using this designation include the Department of Homeland Security.

U.S. Department of Defense

On 24 February 2012, the Under Secretary of Defense for Intelligence published the publicly available , a four-volume manual consolidating all marking of information used by the U.S. Department of Defense. There is a lot more information on the marking, access, and protection of "For Official Use Only" information. Most of the information is in the , but the also contains guidelines on FOUO information.
On March 6, 2020 the DoD replaced DoDM 5200.01 Volume 4 with DoDI 5200.48. The term "FOUO" had been defined in DoDM 5200.01 Vol 4. It is no longer in the replacement document DoDI 5200.48 except as reference as to not requiring a "U" marking in the banner or footer signifying unclassified information as was required with the "old FOUO marking".

Australia

For Official Use Only is one of five categories of the Dissemination Limiting Marker defined by the Australian Government Information Security Management Guidelines. The guidelines state that FOUO should only be used on unclassified information, when its compromise may cause limited damage to national security, Australian Government agencies, commercial entities or members of the public. However unlike the United States usage, the presence or absence of an FOUO marker expressly does not provide any information about the document's status under the Freedom of Information Act.