Arf arf! No, no that kind of seal...
There are a number of U.S. federal agencies which have seals the usages of which are restricted by federal law. For example, about the seal of the Central Intelligence Agency (CIA):
Use of the Central Intelligence Agency Seal Federal law prohibits use of the words Central Intelligence Agency, the initials CIA, the seal of the Central Intelligence Agency, or any colorable imitation of such words, initials, or seal in connection with any merchandise, impersonation, solicitation, or commercial activity in a manner reasonably calculated to convey the impression that such use is approved, endorsed, or authorized by the Central Intelligence Agency. http://www.cia.gov/cia/notices.html#seal
Now I don't know what it's *copyright* status is -- is it a work of the federal government and thus in the public domain, or is it considered an exception? -- but it seems clear to me, anyway, that it is not "free" in the sense required to be listed on Wikipedia Commons. In the United States its usage is restricted fairly heavily, including the "non-commercial" bugaboo. It looks to me like, in effect, this would be a "copyrighted with permission but no commercial use" tag. Which, as I understand it, is verboten.
Of course, when I raise things like this on Commons, I seem to incite a lot of ire from people who want to pick nits about whether or not its usage is limited because of its *copyright* or because of federal laws. I have to admit, for a place which is supposed to care so much about whether or not things are actually free, people seem to think deleting images is the worst thing in the world, even if there is little compelling reason to think they are truly in the public domain. Personally, I'd shoot at first suspicion that something was not really in the public domain -- there would be nothing worse for Commons than to be in continual doubt whether or not its licensing information was correct, it would defeat the entire point -- but that's just me.
Any ideas? I tend to think that any image with this sort of legal restriction does NOT qualify as "free" in the sense required by Commons and is antithetical to its purpose -- to provide a repository of "free" images.
FF