DISTRIBUTION CLERK

The distribution clerk reproduces copies of the messages according to the routing instruction of the inrouter and outrouter. The distribution clerk is responsible for making the required number of copies each subscriber requires and slotting the messages into the appropriate subscriber box.

It is important that the clerk remain alert to prevent slotting messages into the wrong box. This could cause an undelivery situation. The distribution clerk, who handles a great number of messages throughout the watch, must be aware of high-precedence messages and ensure that they are reproduced and distributed in a timely manner for immediate pickup by the subscriber. The clerk must also be "up" on the message center's current SOP for handling special and classified messages.

To prevent viewing by unauthorized personnel, certain messages, such as PERSONAL FOR, AMCROSS, and classified messages, must be placed in envelopes for pickup by subscribers.

Classified messages are placed in two envelopes; the inner envelope is stamped with the classification and any special-handling markings, and then sealed in accordance with local instructions. The outer envelope is marked with the addressee, originator, and DTG of the message, and then sealed.

After reproducing and distributing a message, the distribution clerk places the original copy into a box for filing by the file clerk. When a message is reproduced from the sole copy of a broadcast message, the original copy or a filler must be returned to the broadcast file. If two-ply paper is used on the circuit, the top copy may be used as the master file copy and the bottom copy retained as the circuit monitor copy.

COMMON MESSAGE ELEMENTS

Before covering the basic format of military messages, we will first discuss the time system and precedence categories used in naval communications.

TIME

Time is one of the most important elements in communications. Messages are normally identified and filed by either date-time group or Julian date, depending on the method of transmission.

Date-Time Group

The date-time group (DTG) is assigned for identification and file purposes only. The DTG consists of six digits. The first two digits represent the date, the second two digits represent the hour, and the third two digits represent the minutes. For example, 221327Z

AUG 96 means the 22nd day of August plus the time in Greenwich mean time (GMT). The dates from the first to the ninth of the month are preceded by a zero. We will talk more about the GMT system shortly.

The DTG designation is followed by a zone suffix and the month and year. The month is expressed by its first three letters and the year, by the last two digits of year of origin; for example, 081050Z AUG 96. The zone suffix ZULU (Z), for Greenwich mean time, is used as the universal time for all messages. The exception is where theater or area commanders prescribe the use of local time for local tactical situations. Radiomen never use 2400Z and 0000Z as the DTG of a message. The correct time would be either 2359Z or 0001Z, as appropriate.

GREENWICH MEAN TIME.- In naval communications, the date-time group is computed from a common worldwide standard. To meet the need for worldwide time standardization, the international Greenwich mean time (GMT) system was developed. The GMT system uses a 24-hour clock instead of the two 12-hour cycles used in the normal civilian world.

In the GMT system, the Earth is divided into 24 zones. Zone zero lies between 7 1/2 east and 7 1/2 west of the 0 meridian. The 0 meridian passes through Greenwich, England. The time in this zone (zone zero) is called Greenwich mean time (GMT). The military more commonly refers to this as ZULU time. Both names refer to the same standard.

Each time zone extends through 15 of longitude. Zones located east of zone zero are numbered 1 through 12 and are designated minus. To obtain Greenwich mean time, you must subtract the zone number in which you are located from local time.

Zones located west of zone zero are also numbered 1 through 12 but are designated plus. These zones must be added to the local zone time to obtain GMT. As we will discuss shortly, the 12th zone is divided by the 180th meridian, which is the international date line.

Each zone is further designated by a letter. Letters A through M (J is omitted) designate the eastern, or minus, zones. Letters N through Y designate the western, or plus, zones. The designating letter for GMT is Z (ZULU). The zone number, prefixed by a plus or minus sign, constitutes the zone description. Zones crossing land areas often follow boundaries, natural features, or regional demarcations to keep similar or closely related areas within the same zone.

CONVERTING GMT AND LOCAL TIMES.- Most countries have adopted the GMT system. As a Radioman, you will need to be able to convert local time to GMT. To do this, you must understand the GMT system. Figure 2-9 is a chart showing the time zones of the world. Refer to the chart as you study the material in the next paragraphs.

To illustrate converting local time to GMT, assume that we are in zone R and the local time is 1000R (10 a.m.). Referring to the time chart in figure 2-9, you can see that zone R lies west in longitude from zone zero, and is designated plus 5. Therefore, we add 5 hours to the local time, 1000, to find that GMT is 1500Z. To convert GMT to local time, we reverse the process and subtract 5 hours from the GMT (1500Z) to obtain 1000R.

The U.S. military services use the 24-hour system to express time in four-digit groups. The first two digits of a group denote the hour and the second two digits, the minutes. Thus, 6:30 a.m. becomes 0630; noon is 1200; and 6:30 p.m. is 1830. Midnight is expressed as 0000 (never as 2400), and 1 minute past midnight becomes 0001. Remember, to eliminate any possible confusion, never use 0000Z or 2400Z as the date-time group of a message. The correct time would be either 2359Z or 000IZ.

We mentioned earlier that the 12th zone is divided by the 180th meridian. This meridian is the international date line (IDL) (figure 2-9). This is where each worldwide day begins and ends. A westbound ship crossing the line loses a day, whereas an eastbound ship gains a day. This time zone is divided into literal zones MIKE and YANKEE. The eastern half of zone 12 is designated MIKE (-12), and the western half is designated YANKEE (+12).

Now we come to a very important point in our discussion. Since MIKE and YANKEE are two parts of a single zone, the time in MIKE and YANKEE is always the same. When the IDL is crossed from either direction, the day must change. Since we have already established that there is a l-hour difference between each of the 24 time zones, it is clear that there is always a situation where it is a day earlier or later in one part of the world than it is in another. The primary point to remember about this zone is that it is always the same time in zone MIKE as it is in zone YANKEE, but it is never the same day! You can find more information on time zones in Communication Instructions General (U), ACP 121.

Julian Date

The Julian date consists of seven digits. The first three digits represent the day, and the last four digits represent the hour and minutes. The first day of the calendar year is Julian 001, and each day is numbered consecutively thereafter. For example, in Julian 0311315, 031 is the 31st day of the calendar year (January 31), and 1315 is the filing time.