Section 7.24 - Duration of classification(a) At the time of original classification, original classification authorities shall apply a date or event in which the information will be automatically declassified.(b) The original classification authority shall attempt to establish a specific date or event that is not more than 10 years from the date of origination in which the information will be automatically declassified. If the original classification authority cannot determine an earlier specific date or event it shall be marked for automatic declassification 10 years from the date of origination.(c) If the original classification authority determines that the sensitivity of the information requires classification beyond 10 years, it may be marked for automatic declassification for up to 25 years from the date of the original classification decision.(d) Original classification authorities do not have the authority to classify or retain the classification of information beyond 25 years from the date of origination. The only exceptions to this rule are information that would clearly and demonstrably be expected to reveal the identity of a confidential human source or human intelligence source, or, key design concepts of weapons of mass destruction. In these instances, the information shall be marked for declassification based on implementing directives issued pursuant to Executive Order 13526. In all other instances, classification beyond 25 years shall only be authorized in accordance with § 7.28 and Executive Order 13526.