FACK

FACK in Chat is a feature that allows users to confirm that they have received a message in a chatroom. This feature is useful for ensuring that messages are not lost or forgotten in a chatroom. When a user sends a message, the recipient can confirm that they have received it by sending a FACK message. This message will be visible to all users in the chatroom, so that everyone knows that the message has been received. FACK is a useful tool for ensuring that messages are not lost or forgotten in a chatroom, and it can help to keep conversations flowing smoothly.