The British Admiralty's Room 40 maintained direction finding and interception of German naval signals. It had intercepted and decrypted a German signal on 28 May that provided "ample evidence that the German fleet was stirring in the North Sea". Further signals were intercepted, and although they were not decrypted it was clear that a major operation was likely. At 11:00 on 30 May, Jellicoe was warned that the German fleet seemed prepared to sail the following morning. By 17:00, the Admiralty had intercepted the signal from Scheer, "31 May G.G.2490", making it clear something significant was imminent.