Alert Banners

Spreading news like Wildfire...
First developed during the City Strife to relay updates throughout the free southern quadrants, this complex system of banners and sirens serves to spread crucial information quickly in a short period of time. Because of their ignorance, the tyrants assumed they were merely decorations or attempts by the Faithful to bolster morale. Millenia later during the Genesis Plague, the system was used to warn about the spread and severity of the outbreak, warning families to bunker down and lock their doors. The banners operate much the same as the color-coded flags used on the Oldworld to indicate the strength and severity of incoming tropical storms. Even with the advanced Pegasi, the network is still able to relay information much quicker than it would take to fly. It might come off as antiquated, but in the event of sabotage or technological disruption, it would prove critical to keep the population at large informed.

Writing System

“Looks like word’s gone out,” Rowen said and looked up at a series of banners being raised on a flagpole further down the block. In the distance, they spotted other flagpoles and matching banners rising into the air. “People will hear about this across the city.”
“Wait, you mean that’s how they get news around here?” Kento remarked. Rowen nodded. “They don’t have internet?” Rowen shook his head. “Television? Radio?” Rowen shook his head again. “Morse code? Smoke signals?” Rowen scowled and put his knuckles on his hips.

— Foes From Another World Ch. 21

Flags tend to be roughly two feet long and narrow triangular-shaped. If news is meant to be relayed throughout the immediate area, a set of three primary-color banners are first raised. In the event of similar circumstances, sequential banners are raised notifying of a serious occurrence.
Individual Black and Red banners indicate death from illness.
A red banner underscored by black indicates the presence of similar conditions.
A yellow-and-black checkered banner indicates quarantine or shelter-in-place.
Flags with diagonal lines are used to indicate numbers such as affected households, injuries, or fatalities. Starting from blue to red, the color indicates escalating numbers.

“Bad stuff to go down day after a wedding…” Ryo commented and turned to go back inside, but paused when a shrill siren erupted from the distance. He turned back around and everyone looked up when more banners began rising on the flagpoles. “Anubis?” Ryo asked, concerned when he saw the look in the Elder’s eyes. “You’re the next Thangien aficionado besides Rowen. What’s going on?” Anubis turned to face him, looking worried.
“Red…underscored by black…means this isn’t an isolated incident.”

— Foes From Another World Ch. 21

Geographical Distribution

This specific system is exclusive to formally settled areas of Thanged. Freelanders don't really have a way to spread news quickly unless by chance and mostly fend for themselves. Svampflanders are likewise more-or-less independent.

Brianna came downstairs quietly and glanced about the gathering room. She spotted Anubis standing by one of the windows staring through the filmy curtains at the flagpole. “Anubis?” He glanced at her when she addressed him. “…We’re not going to be going home today, are we?”
“…No, I’m afraid not, my dear. You see that pennant at the bottom there?” Anubis pointed at the pole and the large yellow-and-black checkered flag whipping about in the wind. “It means quarantine has been implemented. People are not to venture outdoors until further notice.”

— Foes From Another World Ch. 21

Bainshaebo: Every house has a pole and set of flags. If new signals are developed, new banners are distributed quickly.
Lonesteads: Flagpoles are shorter than in the city but can be used to warn of predator attack or criminal activity.

Brianna looked back at the pole in time to see the yellow pennant sliding down.
“Look! The flag’s gone! Quarantine’s been lifted! That means the worst has passed!”
“No, it’s been lifted because it isn’t going to do jack squat,” Shannon spoke up and rose out of her seat at the contemplation circle. “This shit’s airborne…”

— Foes From Another World Ch. 21