In Britain, a DA-Notice
(called a D-Notice
until 1993) is an official request to news editors not to publish or broadcast items on specified subjects, for reasons of national security.
D-Notices and DA-notices are merely a request and therefore not legally enforceable and consequently news editors can choose to ignore them without (in theory) official repercussions, although they are generally accepted by the media.
The original D-Notice system was introduced in 1912, run as a voluntary system by a joint committee headed by an Assistant Secretary of the War Office and a representative of the Press Association.
In 1971 all existing D-Notices were cancelled and replaced by standing D-Notices that gave general guidance on what could be published and what could not, and what would require further advice from the secretary of the Defence, Press and Broadcasting Advisory Committee (DPBAC). In 1993 the notices were renamed DA-Notices.
As of 2006 there are five DA-Notices:
- DA-Notice 01:Military Operations, Plans & Capabilities
- DA-Notice 02:Nuclear and Non-Nuclear Weapons and Equipment
- DA-Notice 03:Ciphers and Secure Communications
- DA-Notice 04:Sensitive Installations and Home Addresses
- DA-Notice 05:United Kingdom Security & Intelligence Special Services
A voluntary system of D-Notices
was also used in Australia
starting in 1952 during the Cold War
period and were issued by the Defence, Press and Broadcasting Committee.
Areas subject to a D-Notice in Australia included the whereabouts of the Soviet defector Vladimir Petrov and his wife, and the operations of the U.S.-Australian joint defence communications facility at Pine Gap. A review of D-Notices in 1974 and again in 1982 reduced the many original D-Notices down to four
- D Notice 1 – Capabilities of the Australian Defence Force, Including Aircraft, Ships, Weapons, and Other Equipment;
- D Notice 2 – Whereabouts of Mr and Mrs Vladimir Petrov;
- D Notice 3 – Signals Intelligence and Communications Security; and
- D Notice 4 – Australian Secret Intelligence Service (ASIS).
The system in Australia is believed to now be moribund