D-notice

Newspapers are afraid upon all sorts of minor counts, publishers, with such valiant exceptions as the publishers of this matter, are morbidly discreet; they get Notice D to avoid this or that particular topic; there are obscure boycotts and trade difficulties hindering the wide diffusion of general ideas in countless ways.

His mistake was to select a heavy English Sunday paper which occasionally ran his pieces. The D-Notice forbidding all reference to these events was there ahead of him.