Basic Guidelines For English SpellingsREAD THESE ARTICLES
A government notice issued to news editors requiring them not to publicize certain information for reasons of national security.‘On 3 September, the Ministry of Defence issued a D notice about her case.’‘That said you don't really have to silence everyone at an individual level you simply don't allow it into the mass media, in this country it's called a D notice.’
Second World War D for defence.
Are You Learning English? Here Are Our Top English Tips