D-notice
noun /ˈdiː nəʊtɪs/
/ˈdiː nəʊtɪs/
(British English)- a government notice sent to newspapers telling them that they must not publish particular information about something, for reasons of national security. In 1993 the name was changed to DA-notice, and again in 2015 to DSMA-notice. Word OriginSecond World War: D for defence.