Raven Post - The World of Ice and Fire Glossary | OpenFiction
Raven Post
System
The primary method of long-distance communication in Westeros, using trained ravens to carry messages between castles. Each castle maintains a rookery of ravens trained to fly to specific destinations, tended by the resident maester. While faster than mounted messengers, ravens can be intercepted, killed, or lost, and their routes are limited to where they have been trained to fly.