Signalman 1 & C - Historic Naval Ships Association

Figure 3-2.—Plaindress visual message.basic message format as designed for visualcommunications. Lines 5 through 13 are thenonchangeable elements of the basic message format.All format lines do not necessarily appear in everymessage; however, when used, they will be in the orderindicated.Of the three parts of a message, the most complex(as fig. 3-3 indicates) is the heading. Based on headingcontent, messages may be drawn up in one of threeforms: plaindress, as in figure 3-2; abbreviatedplaindress, featuring a shortened heading; andcodress, used for encrypted messages. We will pointout the differences following the discussion of theplaindress message.PLAINDRESS MESSAGESThe heading of a plaindress message is made upof four components: procedure, preamble, address,and prefix. These components provide operatingpersonnel with necessary information fortransmitting, identifying, delivering, and accountingfor each message.Procedure ComponentIn visual messages, the procedure componentconsists of three elements: call, transmissionidentification, and transmission instructions. The callcontains call signs of the station(s) called and thecalling station. Transmission identification is notnormally used in visual communications except inmessages being relayed. Transmission instructions areconcerned with routing, relaying, and delivering amessage.The beginning procedure component of themessage in figure 3-2 is OHWZ DE NQHS T. Of this3-3