A radiogram is a written message in a standard format, so that many operators can pass it along a chain of stations and it arrives unchanged. The format is essentially the same whether it travels by voice, Morse, packet or Winlink. Handling it well is mostly discipline: copy it exactly and pass it exactly.
The parts
Illustrative example. Preamble: for tracking. Check: words in the text only.
A radiogram has four parts, in this order:
Preamble: the information needed to track the message. It holds the message number, the precedence, the station of origin, the check, the place of origin and the date. Optional handling instructions can also appear.
Address: who the message is for, with a telephone number if possible.
Text: the message itself, kept short.
Signature: who it is from.
The check is the number of words in the text, so a receiving station can tell whether anything was lost or added. Count only the text, not the address or signature. The example's text has 10 words, so the check is 10.
Precedence
Precedence
Abbreviation
Meaning
Emergency
EMERGENCY
life-and-death urgency
Priority
P
important, time-sensitive, but not an emergency
Welfare
W
inquiring about or reporting the health and welfare of a person in an affected area
Routine
R
everything else
Handling follows the precedence: emergency and priority messages go first.
Sending it
Do not change the text. The sender's words are the message, even if you would phrase it differently.
Keep text short and plain. Radiograms are meant to be brief, with no unusual abbreviations.
On voice, pass each part clearly and slowly, with a pause or spoken break between parts, and spell unusual words with the phonetic alphabet.
The receiving station should repeat the check and confirm before the sender moves on.
Where radiograms are used
National and local message-handling networks relay them; see NTS and MARS. During a disaster, health-and-welfare traffic is the common use: people outside the area asking if family are safe. The same fields appear in simplified form on agency forms, such as the ICS-213 described in The Incident Command System.