28 CFR §17.26

1. (a)Persons need not possess original classification authority to derivatively classify information based on source documents or classification guides.
2. (b)Persons who apply derivative classification markings shall observe original classification decisions and carry forward to any newly created documents the pertinent classification markings.
3. (c)Information classified derivatively from other classified information shall be classified and marked in accordance with the standards set forth in sections 2.1-2.3 of Executive Order 12958, the ISOO implementing directives in 32 CFR 2001.22, and internal Department directions provided by the Department Security Officer.