The Arrow-Code was developed as a foolproof way for Heralds to convey basic messages. It is why all Heraldic Trainees are taught archery, and why Heralds arrows are fletched with mud-gannet feathers. While goose feathers make much better arrows, the mud-gannet feathers have heavily, evenly spaced barbs. This allows the arrows to be virtually identical to one another, and for a Herald to count the barbs for the code.
Each Herald is issued a pattern, which is encypted and recorded in the Secret Records. The encryption key is only known to the Monarch, the Monarch's Own Herald, the Seneschal, the Seneschal's Herald, and the Dean of the Herald's Collegium. In the case of 'present-day' Valdemar, this is Queen Selenay, Herald Talia, Lord Palinor, Herald Kyril and Dean Elcarth. Only Kyril and Elcarth have every pattern memorized as well.
The pattern broken into the fletching tells the recipient which Herald sent the message, and that it isn't a trick, which might be the case without the Herald's personal 'signature'. The message itself is conveyed by the colors banding the arrow shaft:
- White = All is well. Usually used to signify that another Herald is in the area.
- Green = Send a Healer
- Purple = Send a priest
- Gray = Send another Herald
- Brown = Watch for a message. There's trouble and the Herald sending the arrow needs to elaborate further and may be delayed
- Blue = Treachery
- Yellow = Send military aid
- Red = Great danger, come with all speed
- Black = Death and/or catastrophe
In addition, a headless arrow in any color announces a Herald's death. A broken arrow in any color signifies a disaster beyond all hope, rescue should not be attempted.
The number of bands of a color may also indicate a number to be sent. For instance, when Kris sent Talia an arrow over the walls of the plague-stricken town of Waymeet, it had three bands of green, requesting three Healers be sent. Each band of yellow indicates another military unit, and sending every yellow-banded arrow means to send the entire army.
The code is explained in Arrow's Flight, when Kyril teaches it to Talia before she leaves on her internship circuit.