The SECRET stamp is the most powerful weapon ever invented. – Leo Szilard
Over the course of working on Restricted Data: The History of Nuclear Secrecy in the United States, I came across a lot of “secrecy stamps” — inked stamps that indicate that a given document is secret. These totemic representations of a secrecy regime, of course, have a function beyond their symbolism: they are part of the document control regime that allows one, at a glance, to know how a document must be handled, and who can be allowed to see them. In the American context, the stamps on a document often reveal the document’s movement through the secrecy regime, as a document — in principle — should contain the entire history of that document’s secrecy statuses over time.
Below are some photographs I took in the archives over the years of some of the more visually striking examples of secrecy stamps I came across. All of these photographs are copyright Alex Wellerstein, but are free to use in a non-commercial context if attribution is given. If you would like permission to use them in another context, just get in touch.
The smudged quality of this stamp makes it seem aesthetically sinister, although it is likely a reflection of the banality of applying these stamps to page after page.The outsized nature of this stamp makes it rather exceptional — it is a lot larger than most of them I’ve seen — as its its convenient and dramatic placement over the letterhead of the US Atomic Energy Commission from 1947. I frequently use this as the cover slide to presentations about Cold War nuclear secrecy.In the United States, secret documents are modified by stamps to indicate their changing status. This one appears to have been downgraded, over the years, from SECRET to OFFICIAL USE ONLY, the latter being a form of controlled-but-unclassified information (OFO data is not meant to be distributed out of the government, but there are no legal penalties for its distribution). The overlapping messiness of this particular set appeals to me aesthetically.Secrecy stamps (as one can readily see from these many examples) come in many different typefaces. It isn’t clear to me how standardized they were across various organizations. This one is particularly “clean” relative to many of the others here.Restricted Data is its own classification category separate from National Defense Information (like SECRET, TOP SECRET, CONFIDENTIAL), and RD stamps frequently have a little paragraph explaining the statutory basis for the category (the Atomic Energy Act). This document, with a particularly clean RD stamp on it, is classified as both CONFIDENTIAL and RESTRICTED DATA, and anyone who would be authorized to see it would have to have clearances for both secrecy regimes.EYES ONLY is a stamp that indicates that a given document is so sensitive that it cannot be copied or transmitted in any form — it can only be shown to people in its original form, that eyes are the only ways to deal with it. I always felt this was a strange expression, and it is a relatively rare stamp to come across in my experience.Secret documents in the United States frequently contain long, difficult-to-read stamps like this one explaining the statutory basis of the secrecy (in this case, invoking the Espionage Act). It always feels a bit overkill to me; anyone with access to these documents in principle ought to know that there are quite a number of ways that misusing them can go wrong, and stamping each document with something like this seems a bit much. But clearly some regulation required it, and the secrecy regimes are very orderly regulatory regimes.In principle, you should never be able to see a stamp that says SECRET unadorned unless the document is still secret. Obviously that has not been observed historically — none of the documents on this site are still secret! When a document has been declassified, any stamps are supposed to be struck-through to indicate the change in status. This one, addressed to Glenn Seaborg, eliminates one SECRET stamp with a stamp of barred lines and a DECLASSIFIED heading. I also like the particularly “modern” look of the typeface used for the original SECRET stamp.This is a cover to a draft of the Smyth Report (discussed at length in my book). This draft is particularly early, when it was briefly called NUCLEAR BOMBS. As the book explains, this was seen as too obscure by the military, and it was changed to ATOMIC BOMBS, and then that title itself was inadvertently not applied to the final release. I like this image both for the cancelled SECRET stamp at the top (which is in an interesting typeface), but also because of the use of the red pencil to change NUCLEAR to ATOMIC.Redaction in documents usually is non-destructive to the document itself (and a copy is kept of the original), though I have occasionally found instances of physical redaction like this one, where classified data (in this case, numbers relating to the production data of nuclear weapons neutron initiators in the 1940s) was cut out by means of a razor of some sort. Finding a document like this is very rare, however. I put a blank piece of paper behind the document in order to take the photograph.As previously mentioned, classified documents in principle contain their entire classification history on them. This one is particularly messy, running the gamut from TOP SECRET down to CONFIDENTIAL, running the risk of obscuring the text itself (as these stamps sometimes do).The US Atomic Energy Commission had a very striking seal, and had the quality (which its successor organizations’ seals do not) of reproducing well at small sizes. This particular stamp is from AEC letterhead in the 1940s; the staple at top left gives a sense of scale.This is the first page of the Report of the Committee on Declassification (the Tolman Committee Report), from November 1945, which set up the epistemological and regulatory framework for the postwar nuclear secrecy and declassification regime in the United States. (Its creation, contents, and import are discussed in the book.) As it indicates, this is the first copy of the report produced, and it bears a range of stamps from RESTRICTED DATA and TOP SECRET, down to SECRET and finally the cancellation of its own classification (per its the guidelines the report itself sets out). It is of note that the RESTRICTED DATA stamp on it dates from well after the report’s creation, as it invokes the Atomic Energy Act of 1954 as its statutory authority.This isn’t included because of its stamps (though it has a few), but because of its signatures. It is not every day one is able to handle a document with so many Nobel Prize winners’ signatures on it (Urey, Compton, Lawrence), plus so many other interesting people (Oppenheimer, Tolman). This particular copy of the report was not filed in a folder, but sitting loose in an archival box, and was a surprise to find in there (I had seen other copies of the report elsewhere, but not the original, first edition of it).In principle, you and I should never see a cover sheet like this — it indicates (as it says on its cover) that it hides classified information behind it. In practice, these are frequently left in the boxes of declassified documents at the National Archives, which gives one a sense of what a truly classified file might look like. This one is classified SECRET–RESTRICTED DATA. I have been told by people who have recently worked in the government that this style of cover sheet is still quite common. The advantage of this sort of sheet is that it indicates the classification status of a document without one actually seeing the document itself first — so that a good-natured person could, I imagine, quickly avert their eyes.
![two smudged stamps overlaid, one reading SECRET, the other reading OFFICIAL USE [ONLY]](https://i0.wp.com/alexwellerstein.com/wp-content/uploads/2021/01/overlapping-stamps.jpg?ssl=1)
