Section 200.507 - Declassification dates on derivative documents(a) A document that derives its classification from information classified under Executive Order 12356 of predecessor orders shall be marked with the date or event assigned to that source information for its automatic declassification or for review of its continued need for classification.(b) A derivative document that derives its classification from the approved use of the classification guide of another agency shall bear the declassification date required by the provisions of that classification guide.47 FR 47236, Oct. 25, 1982