What information is contained in the preamble of a formal traffic message?

In formal amateur radio message handling (the National Traffic System or NTS), a radiogram is divided into distinct parts: the preamble, the address, the text, and the signature. The preamble serves as the administrative header of the message. The preamble contains the metadata needed to track the message from its origin to its destination. This includes the message number, the precedence (urgency), the handling instructions, the station of origin, the word count, and the date and time it was created. While the address of the recipient is a crucial part of the message form, it is its own separate section. Contact information like email addresses and telephone numbers belong in the address block, not the tracking-focused preamble.