Deep Impact begins when an Intrepid Reporter, looking for a scoop on an apparent political affair involving a woman named Ele, turns out to know too much by the governments reckoning just by knowing that name- which turns out to be an acronym for Extinction Level Event.
In Close Encounters of the Third Kind, the organization(s) involved in the First Contact mission. They fake a massive disaster simply to clear the area of witnesses - and disguise their operatives moving in massive amounts of equipment as legitimate national guard emergency operations. Ask too many questions and you'll be arrested for trespassing, brought in for questioning, and wake up in a hospital suffering from "accidental exposure to nerve gas".
At one point in Cryptonomicon, Lawrence finds himself bored in Australia, and wants to make himself useful as a codebreaker. He briefly has trouble doing so, because his security clearance is so high that he can't even admit its existence to any of the people he'd be making himself useful to, so he has to track down someone who will give him papers with a clearance low enough that he's allowed to talk about it.
A recurring theme in Carole Nelson Douglas' Irene Adler novels, especially the later ones involving prostitution, serial killers, Jack the Ripper, Krafft-Ebbing's Psycopathia Sexualis, female circumcision, abortion, illegitimate births, secret adoptions, etc. The narrator, Nell Huxleigh, is a Shropshire parson's daughter with little experience of sex generally, now living with the more worldly ex-Pinkerton and former opera diva Irene Adler Norton. Propriety demands that polite people (and women particularly) know nothing of such matters much less discuss them, but as Irene points out more than once, ignorance of such things puts people (women particularly) in danger from them.
This starts coming up in later books of The Lost Fleet series, as the 100 year long war has engendered severe mistrust and paranoia among both government and military and they have a hard time shaking the habit even after it ends. The many morally questionable activities during the war don't help. Thus we get events like the Fleet Admiral, purely by chance, finding that only he has high enough authority to learn that someone has a mental block preventing them from spilling on a bioweapons project- a block the person couldn't even admit existed, much to their mental detriment.
The White Tower of The Wheel of Time got a bit carried away with this. The unaltered records of the Tower's history are Sealed to the Flame, meaning that only members of the ruling council are allowed to read them. The existence of any such records is also Sealed, as is the existence of a law forbidding the councilors from revealing any of this to outsiders.
In Doctor Who, when the Doctor meets up with the amnesiac Brigadier, teaching at a boys' school, the Brigadier's attitude undergoes an abrupt change when the Doctor mentions UNIT — he still doesn't know him, but anyone with sufficient secret clearance to mention it ought to know better than to talk like that.
The Oblivion War in The Dresden Files. An outsider as much as learning that there is such a thing already constitutes a major loss for one side (Venatori) and a major victory for the other. Understandably, the Venatori are extremely short on hands.
Towards the end of Call of Juarez: Gunslinger, Ben The Bartender reveals himself as Roscoe "Bob" Bryant, one of the outlaws who killed Silas' brothers by asking Silas' about one of his marks and referring to him by his (the mark's) surname, which Silas never mentioned in his narration.
The Simpsons: the Stonecutters. Homer keeps asking about it, to which Lenny answers cryptically and Carl responds, "Shut up!" The third time this happens Carl is in mid-sip of his coffee, so he gives Lenny a dirty look and Homer tells Lenny to shut up.
So called "Super-injunctions" in the United Kingdom (which are controversial, since judges have granted them without legislation from parliament allowing them to do so) not only protect the identity of whoever's covered by them, but also protect the fact that there's even an injunction from being reported. Although there are loopholes; Some MPs have used parliamentary privilege to speak out about them (newspapers can report what they said freely), papers only distributed in Scotland and other British countries with devolved parliaments are technically not under the jurisdiction of British courts and it's somewhat harder to enforce on the internet. By the way, in case you were wondering Ryan Giggs had an affair.
Most governments also have some sort of law or legislation which makes them able to have sensitive documents treated like this. Private companies can do the same with "non-disclosure agreements" (although being contracts the law can override them).
In government there is what is called a "Gag order" (no, not ordering someone to joke:). In the United States, a "National Security Letter", an administrative subpoena used by the FBI, has an attached gag order which restricts the recipient from ever saying anything about being served with one.Most normal subpoenas allow for notice to the person who's information is being requested, so they may dispute the government's (or in civil cases, the other party's) need for it. But the gag order prevents them from doing so, since they don't even know it exists.
Some U.S. libraries protested this by posting a sign, "No National Security Letters have been received by this library", with the idea that if they were served with one, they would remove the sign, thus legally letting people know without violating the gag order. In addition, people attempting to sue the U.S. government for breaking the law and violating their rights must first prove their rights were violated. However, that is classified information. A nice Catch22. One person who the government accidentally sent a copy of the illegal spying report was forced by the courts to return it to the government and thus their lawsuit was then thrown out for lack of evidence.
Allegedly, in the Allied command in WWII, those who had advance knowledge of the D-day plans were referred to as "BIGOTs", on the theory that even in the 1940's no one would admit to being a bigot, and thus those who asked too many questions would get sidetracked by the accusation. The sign - countersign conversation started out something like so:
Are you a bigot?
Yes, I'm a bigot.
Five hats means that five tropers think it is ready to publish.
You are saying that you think this draft is ready to be published. That means the description is not ambiguous,
it doesn't duplicate an existing trope, there are at least three examples, and the title makes sense.
Is that what you meant to do?
You are saying this draft has a ready-to-publish hat it does not deserve and you are taking it back.