Secretary of the Navy Josephus Daniels All Navy Communication Cable
March 29th, 1918.
VICE ADMIRAL SIMS, FIFTY THREE ALNAV.
OPNAV 4373 (RADICODE) To ships and stations having following (BOX F) Recent events have accentuated the possibility of an intensive campaign directed by the Germans comma and carried on through their paid agents comma directed particularly against US Shipping of any description period Such a campaign would be supplemental to the submarine campaign and directed at the delay and destruction of American Ships comma particularly those engaged in furthering the military and naval operations of the United States period To safeguard against such enemy measures the closest scrutiny and inspection should be carried out at all times on all ships comma of the personnel comma supplies comma and cargoes carried in order to guard against any dastardly attempts at incendiarism or destruction period Wherever practicable trusted agents of our own should be employed for counter espionage period Too much care cannot be exercised to safeguard our ships by every means possible 23029 4373.
Secretary of the Navy.
Source Note: Cy, DNA, RG 45, Entry 517B.