classified marking guide (dec 2010) - the Security Training Portal.

If the source documents contain multiple 25X markings, only one of the markings is requiredto be placed on the derivative document, as long as it is the one with the longest duration ofclassification. For example:Document 1 – 25X3, 20350215Document 2 – 25X5, 20320510Document 3 – 25X4, 20301220The marking from document 1 (25X3, 20350215) would be carried over to the derivativedocument and placed in the “Declassify On” line.When determining the most restrictive declassification instruction among multiple sourcedocuments for placement in the “Declassify On” line, adhere to the following hierarchy:1. “50X1-HUM” or “50X2-WMD” exemptions, oran approved exemption (“50X1” thru “50X9”)reflecting the ISCAP approval for classificationbeyond 50 years in accordance with section3.3(h)(2) of the Order.2. “25X1” through “25X9” exemptions, with a dateor event.3. A specific declassification date or event within25 years.4. Absent guidance from an original classificationauthority with jurisdiction over the information, acalculated 25-year date from the date of thesource document.Reference: 32 C.F.R. Part 2001.22(e)(4)- 19 -