Priority, Immediate, and Flash. Figure 2-13 shows examples of the different types of precedence. complete information concerning message pre- cedence is contained in Naval Telecommunica- tions Procedures (NTP), Telecommunications Users Manual, NTP 3(H). Routine. —Routine is the precedence assigned to all  types  of  traffic  that  justify  electrical transmission but are not of sufficient urgency to require a higher precedence. The Routine pre- cedence is identified by the prosign R. Priority. —Priority is the precedence reserved for messages that furnish essential information for the conduct of operations in progress. That is the highest precedence normally authorized for administrative messages. Priority precedence is identified by the prosign P. Immediate.   —Immediate  precedence  is reserved for messages relating to situations that gravely affect the national forces or populace and require immediate delivery to addressees. Im- mediate precedence is identified by the prosign O. Flash. —Flash precedence is reserved for initial enemy contact reports or operational combat messages of extreme urgency. Message brevity is mandatory in Flash messages. Flash precedence is identified by the prosign Z. Another precedence is the Emergency Com- mand. The Emergency Command precedence (ECP) is not commonly used but preempts all other precedence. Its use is limited to the National Command Authority, certain designated com- manders of unified and specified commands, and specifically designated emergency action com- mand and control messages. When used, ECP is identified by the prosign Y. Messages having both action and information addressees may be assigned a single precedence or a dual precedence. A dual precedence exists when a higher precedence is assigned to action addressees than to information addressees. The assignment of a dual precedence must be con- sidered on all messages with information ad- dressees when other than routine precedence is assigned to the action addressee(s). REACTION  TIME.  -The precedence assigned to a message has no direct effect on the time by which a reply must be sent or on the precedence assigned to that reply. Each activity must establish its own requirements concerning the acknowledgment of messages. The following factors should be considered when submitting a reply to a message: 1. Does the message have a reply due date? 2.  Must  the  reply  be  forwarded  by telecommunication message, or can it be sent by naval letter or NAVGRAM? Regardless of the reaction times established locally, Flash and Emergency Command pre- cedence messages requiring a reply must always be handled as quickly as possible. In some cases, you may be required to forward a reply to the originator in less than 30 minutes. Date-Time Group The date-time group (DTG) is assigned to messages for identification purposes only. The DTG consists of six digits followed by a time-zone suffix (for example, 021930Z). The first pair of digits (02) denotes the day of the month; the second pair (19) indicates the hour; and the third pair (30), the minutes. All DTGs are expressed in Greenwich Mean Time (Z) unless otherwise directed by higher authority. In addition, the abbreviated month and year of origin are ap- pended to the DTG. Therefore, the DTG 021930Z JAN 91 would be identified as a message being officially released from a communications facility for transmission at 1930 hours, Greenwich Mean Time, on the 2nd of January 1991. Although not considered as part of the date- time group, the originator’s name must be included in the identification of a specific message. For example, NETPMSA Pensacola FL 032115Z MAY 91 indicates a specific message originated by Naval Education and Training Program Management Support Activity, Pensa- cola, Florida. However, a message identified only by the DTG 032115Z MAY 91 is not properly identified since any command in the Navy could have released a message with the same DTG. Message Format Figure 2-14 shows the Joint Message Form (DD-173/2). Naval Telecommunications Pro- cedures (NTP), Telecommunications  Users Manual,  NTP 3(H), and U.S.  Navy  Plain Language Directory, NTP 3, SUPP-1 (K), give the fundamental format and procedures for preparing the naval message. ADDRESS COMPONENTS. —The address consists of the plain language address (PLA); the message originator; and the action, information, 2-33