an official notice from the British government advising the press not to publish certain information because it would harm the country if it were to be made public. 'DSMA' stands for ''Defence and Security Media Advisory'. Until 1993 DSMA-notices were called D-notices and then, until 2015, DA-notices.
اطلاعیه مشورتی دفاع و امنیت, اخطار عدم انتشار اطلاعات