Open secret

An open secret is a concept or idea that is "officially" secret or restricted in knowledge but in practice may be widely known; or it refers to something that is widely known to be true but which none of the people most intimately concerned is willing to categorically acknowledge in public.

One famous "open secret" is that of Area 51, a United States military base containing an aircraft testing facility. The U.S. Government did not explicitly affirm the existence of any military facility near Groom Lake, Lincoln County, Nevada until 2013, when the CIA released documents revealing that the site was established to test spy planes. While the general location of the base is now officially acknowledged, the base does not appear on government maps or in declassified satellite photography. Yet despite this, the base was demonstrably and widely acknowledged to exist for many years before the CIA officially confirmed its existence. The immense secrecy has made it the frequent subject of conspiracy theories and a central component to UFO folklore.

Likewise, Delta Force can be considered an open secret, since its existence has been denied in the past by the United States Government.

Camp Mirage is the codename for a former Canadian Forces forward logistics facility located in Dubai, United Arab Emirates. The facility was established in late December 2001 and, though not officially acknowledged by the Canadian Forces, was considered an open secret.

The existence of the British Secret Intelligence Service (MI6) was widely known for several decades before the government's official acknowledgement of the organisation in 1994. Its Australian counterpart, ASIS, was the subject of a newspaper exposé years before its existence was officially acknowledged.

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