Coordinating ground forces is hard enough, organizing a team of fire-breathing beasts capable of flying up to 60 miles per hour is virtually impossible. It is for this reason that large units of dragon-riding forces are not prevalent in nearly all powerful armies. In Khetzala, however, it's a different story.
Thanks to their Savanna Plains Racer heritage, Khetzali War Dragons are able to light up certain sections of their wings in asymmetrical patterns in order to communicate with their fellow dragons. The Khetzali took advantage of this skill to devise a solution to communication during chaos: Flash Code.
Language of Hunters
Savanna Plains Racers, the genetic ancestors of the Khetzali War Dragon, have been using a primitive version of Flash Code for centuries. When hunting as a pack, the dragons will ignite certain portions of their wings just before performing certain maneuvers. This helps them coordinate attacks and avoid mid-air collisions with each other.
Racers can flash upwards of fifteen different messages a minute, all with spot-on accuracy. The older and more experienced the dragon, the more complex and precise their messaging is. They can intepret these messages just as fast, thanks to their exceptional eyesight and intelligence.
Refinement and Use
War Dragons inherently know the basic signals used by Racers. These signals are still used on the battlefield, and are the first set of signals that prospecting dragon riders learn.
Flash Code adds over one hundred new signals, many of which are just variations on the basics. Frequent battle formations, letters and numbers, geographic landmarks, and sometimes even names are all possible to be signaled using Flash Code. Each dragon rider in a unit has their own flash pattern assigned to them so that the rest of their unit can address them specifically during battle. Units also tend to come up with their own personal spins on the code.
What Did You Just Sign to Me?
Soldiers are people too, and just like everyone else, they sometimes possess a rather impolite sense of humor. Flash code signals representing curses are commonly known across dragon riders, despite never being officially taught during training. There are also a few choice signs that don't need training to understand. This language is ignored for the most part, but if you're caught flashing something rude during a formal event... watch out.
Ordering the dragon to use these specific signals during flight is done with a combination of voice commands, taps or tugs on the dragon's body or reigns, and the dragon's instinct. It takes hundreds of hours of training to get the dragon and rider accustomed to each other to the point that they can pass along information flawlessly.
All Khetzali military officials--even those not directly related to the dragon riders--can interpret the majority of Flash Code signals. Outside of the military, knowledge on Flash Code signals are carefully guarded to avoid them falling into the hands of enemies.
Even if the Codes were viewed by the wrong eyes, it would be difficult to use them to Khetzala's disadvantage. The speed at which the signals are flashed on the already moving dragons is a challenge to interpret even by trained individuals.