Description of the duration of classification (see Classified evidence in a court martial):
When information is classified, the OCA must also decide when that information should be made available. The idea is to decide on a time after which the information would not be expected to damage national security.
The OCA can either decide on a time period or an event after which the information should be declassified. The default period of time is ten years, unless an earlier date can be identified. An OCA cannot decide on a time period of more than ten years; it can however decide on successive ten year periods. However, 7 exceptions exist to this rule:
“an OCA can exempt from declassification information beyond the 10-year limit, if release would:
(1)Reveal an intelligence source, method, or activity, or cryptologic system or activity;
(2)Reveal information that would assist in the development or use of WMD;
(3)Reveal information that would impair the development or use of technology within a United States weapon system;
(4)Reveal foreign government information;
(5)Damage relations between the United States and a foreign government, reveal a confidential source, or seriously undermine diplomatic activities that are reasonably expected to be ongoing for longer than 10 years;
(6)Impair the ability of United States government officials to protect the President, Vice President, or other individuals for whom protection services in the interest of national security are authorized;
(7)Violate a statute, treaty, or international agreement.”