Can anyone explain DA notices

[Playpal]

Any info gratefully accepted. Are they covered by the official secret act

[EdithWeston]

The aim of the DA Notice System is to prevent inadvertent public disclosure of information that would compromise UK military and intelligence operations and methods, or put at risk the safety of those involved in such operations, or lead to attacks that would damage the critical national infrastructure and/or endanger lives.

It's a voluntary code, overseen by a committee which liaises between the British media and Government departments which have responsibility for national security.

There is lots of information on the DA system website here.