32 CFR 2400.12: Identification and markings.
(a) At the time of original classification, the following information shall be shown on the face of all classified documents, or clearly associated with other forms of classified information in a manner appropriate to the medium involved, unless this information itself would reveal a confidential source or relationship not otherwise evident in the document or information:
(1) One of the three classification levels defined in § 2400.6 of this part;
(2) The identity of the original classification authority if other than the person whose name appears as the approving or signing official;
(3) The agency and office of origin; and
(4) The date or event for declassification, or the notation “Originating Agency's Determination Required.”
(b) Each classified document shall, by marking or other means, indicate which portions are classified, with the applicable classification level, and which portions are not classified. The Director OSTP may, for good cause, grant and revoke waivers of this requirement for specified classes of documents or information. The Director of the Information Security Oversight Office shall be notified of any waivers.
(c) Marking designations implementing the provisions of Executive Order 12356, including abbreviations, shall conform to the standards prescribed in Directive No. 1 issued by the Information Security Oversight Office.
(d) Foreign government information shall either retain its original classification or be assigned a United States classification that shall ensure a degree of protection at least equivalent to that required by the entity that furnished the information.
(e) Information assigned a level of classification under predecessor Executive Orders shall be considered as classified at that level of classification despite the omission of other required markings. Omitted markings may be inserted on a document by the officials specified in § 2400.18 of this part.