[152]   Communication Intelligence Summary, 15 November 1941
General.-Traffic volume normal, with a number of general address  messages originated by Communication Division, Tokyo, to Radio Officers,  Ominato, U. E. 9 (D. F. Station in Marshalls), Jaluit, Palao, Truk,  Saipan, Takao and Sama Radios, Staff Communication Officers All Major  Flagships, Staff Communication Officer South Expeditionary Force and two  apparent collective shore addresses. Traffic from all stations mentioned  except Sama and Ominato to D. F. Control and Plotting Room Tokyo  information to Staff Communication Officer Combined Fleet was exchanged.  No messages of the D. F. type were detected so it is presumed that the  interchange had to do with arrangements for drill or organization of the  net. The Minister of the Navy originated one Alnav and one to all Major  Commands and collective shore. Tokyo Personnel and Tokyo Communication  Division originated several to collective fleet and shore. Significance  is not determined though it is believed possible that a further partial  change of shore and air calls may be in prospect. The Empire air station  net was normally active using tactical calls. Secretary First Fleet I  originated one Urgent Code to unidentified (MINI 55), Staff  Communication Officer Carrier Division Four (at Sasebo) and Commanding  Officer of Batdiv Three flagship.
Combined Fleet.-Same as yesterday, same units (Batdiv Three, Desrons One  and Three) associated through traffic with South Expeditionary Force.  CinC Second Fleet was the most active originator and appeared to be  arranging operations of units involving First, Second, Carrier and Air  Units.
Third Fleet.-Inactive.
Fourth Fleet.-Apparent movement of Fourth Fleet units in prospect or  underway with continued emphasis on the Marshalls Area. CinC. Fourth  traffic still being handled from the Truk area, with Airron Twenty-four  (Kamoi) and associated Yokohama and Chitose air units involved in some  movement direction undetermined. All Marshall Island activities,  including unidentified Army Forces, exchanging traffic freely.
Submarine Force.-Little activity detected. It is believed that some  submarine activity is operating or preparing to operate in the Marshall  area, from communication arrangements underway between Staff  Communication Officer
Submarine Force and same Fourth Fleet, information to Jaluit. Jaluit has  been heard working on various frequencies, using tactical calls and  procedure associated with submarine operations, but no identifications  of calls used have been made.
[153] Air.-Continued air traffic to and from Takao area, with unidentified  Airron formerly YOME 7) including South Expeditionary Force and Sama  addressees n traffic. Composition of this force and purpose still  speculative but believed o be preparing to move southward to work with  the South Expeditionary Force.
The large number of alternate calls used by major forces renders  analysis of traffic headings very slow and difficult, but  identifications and recoveries of alternates are improving as a greater  volume of November traffic becomes available for research.