A chat system for a digital television network comprises a digital operator head end system for broadcasting to subscriber decoders. The head end system comprises a chat room creation device which communicates with a chat server to create, cancel and/or join an event related chat room, a trigger device which may be programmed to activate itself at the occurrence of an event and automatically sends a request for creation of a chat room to the chat room creation device, a broadcast device used for preparing a transmission of information to the subscriber decoders, and a notification server to generate a notification message to be transmitted by the broadcast device, the notification message being related to the creation of an event related chat room.