Realm wide trade chat relay system.
If someone using OTC is in a major city, trade will be relayed to you no matter where you are. if you're outside the city, you can post a message to OTC and everyone outside the city will see it.
To talk into OTC-chat, just type "/otc hello" and the message will be displayed in your chat area.
usage: /otc [on|off|-v|message to otc-chat]