Classification markings: banner lines, portion marks, and the classification authority block

Classification markings are the standard labels that show which information in a document is classified, at what level, and for how long. Executive Order 13526, signed December 29, 2009, sets the three levels. The marking formats are in subpart C of Part 2001 of Title 32 of the Code of Federal Regulations (CFR), the Information Security Oversight Office (ISOO) directive. Section 2001.20 says markings must be applied uniformly and conspicuously to "leave no doubt" about classified status, level of protection, and duration. ISOO's marking booklet, Revision 4 of January 2018, lists the required elements: portion marks, the overall marking, and a classification authority block.

Three levels and no others

Section 1.2 of the order defines the levels by the damage that unauthorized disclosure could reasonably be expected to cause: exceptionally grave damage for Top Secret, serious damage for Secret, and damage for Confidential. Except as a statute provides, no other terms may identify U.S. classified information. If there is significant doubt about the right level, section 1.2(c) says the information is classified at the lower level. Section 2001.24(a) repeats the rule for markings.

Section 2001.20, in the text current as of October 20, 2026, also limits variation. Except in extraordinary circumstances, or with approval from the Director of ISOO, markings may not deviate from the prescribed formats. When markings cannot be affixed to an item, the originator gives holders written instructions instead. The booklet states that it rescinds all previous booklets and that its markings are for illustration only.

The banner line

The overall marking is the highest level of any one portion, under section 2001.21(b). It goes at the top and bottom of the outside of the front cover, the title page, the first page, and the outside of the back cover. Each interior page is marked at top and bottom with either the highest level on that page, including "Unclassified" where it applies, or the overall level of the document. Dissemination control markings, when used, appear at the top and bottom of each page after the level, under section 2001.24(j)(3).

The Department of Defense (DoD) marking manual, DoD Manual 5200.01, Volume 2, dated February 24, 2012 and incorporating Change 4 of July 28, 2020, names this overall line the "banner line." In DoD documents the level is written in English, spelled out completely, and in uppercase letters. Double forward slashes separate the level from control markings, and a single slash separates entries within one category. One of the manual's examples reads SECRET//REL TO USA, AUS, CAN, GBR. The manual warns that page-by-page markings need extreme caution, because edits or repagination can move information onto a page whose marking no longer fits.

Portion marks

Section 2001.21(c) defines a portion as ordinarily a paragraph. The section also counts subjects, titles, graphics, tables, charts, bullets, sub-paragraphs, and classified signature blocks. Each is marked with a parenthetical symbol immediately before it: (TS), (S), (C), or (U). If every sub-paragraph or sub-bullet has the same level, one mark at the start of the main paragraph is enough. If levels differ, each segment is marked, and a higher sub-bullet does not raise its parent.

The booklet says portion marking is required on all classified documents, including e-mails, and on unclassified documents on a classified system. It recommends spelling out the level on a graphic. In DoD portion marks, control markings follow the level after double slashes, as in (S//REL).

Portion marking has a consequence downstream. A document left unmarked under an ISOO-approved waiver must carry a warning that it may not be used as a source for derivative classification, under section 2001.24(k)(4). Waivers are temporary and carry expiration dates.

The classification authority block

The block records who classified the document and when it declassifies. Section 2001.21(a) sets the original lines. Section 2001.22 sets the derivative lines.

Line	Original classification	Derivative classification
Classified By	Name and position, or personal identifier, of the original classification authority	Name and position, or personal identifier, of the person who created the document
Reason	1.4 plus the category letter, such as 1.4(g)	Not carried forward
Derived From	Not used	Source document or classification guide, with agency, office, and date, or "Multiple Sources"
Declassify On	A date or event up to 10 years, a date up to 25 years, or 50X1-HUM or 50X2-WMD	Carried forward from the source; the longest duration when there are several sources

Numeric dates take the form YYYYMMDD. The booklet adds that a derivative "Classified By" line names a person, not a group, office, or team name. The date of origin must also be immediately apparent, under section 2001.21(e).

The DoD manual requires the block on the face of each classified document. Bottom left is most typical, but available space decides the placement. On e-mails, messages, and web pages, the block may appear as a single line.

What to check

• Does the banner line state the highest level of any portion, at the top and bottom of the cover, title page, first page, and back cover?
• Is every portion, including titles, subjects, graphics, and bullets, marked immediately before the portion?
• Does the "Classified By" line name a person by name and position or personal identifier, rather than an office or team?
• Is the "Declassify On" entry a YYYYMMDD date, an event, or 50X1-HUM or 50X2-WMD?
• Does a document that is not portion marked carry the warning that it may not be used as a source for derivative classification?
• In a DoD document, do double slashes separate the level from control markings, and single slashes separate entries within one category?

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Sources

1. 1Executive Order 13526, Classified National Security Information · National Archives, Information Security Oversight Office (order of December 29, 2009)
2. 232 CFR 2001.20 General · Electronic Code of Federal Regulations
3. 332 CFR 2001.21 Original classification · Electronic Code of Federal Regulations
4. 432 CFR 2001.22 Derivative classification · Electronic Code of Federal Regulations
5. 532 CFR 2001.24 Additional requirements · Electronic Code of Federal Regulations
6. 6Marking Classified National Security Information, Revision 4, January 2018 · Information Security Oversight Office (ISOO Handbook 2018-01)
7. 7DoD Manual 5200.01, Volume 2, DoD Information Security Program: Marking of Information (February 24, 2012, incorporating Change 4, July 28, 2020) · Office of the Under Secretary of Defense for Intelligence and Security (esd.whs.mil copy captured February 2, 2026, Internet Archive)

Where this shows up in our work

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