Team Fortress 2 features a global messaging system, which allows Valve to send custom notifications to all in-game players at once. These are referred to as system messages. System messages are custom messages sent from Valve and are therefore not translated for non-English players. The system is used rarely, and usually to broadcast maintenance notifications, scheduled broadcasts, or tournaments.
System messages appear in both the chat area and in the notification area and are accompanied by a beeping sound.