Access the global text chat in the game by pressing: t. Anything you type in the global chat will be seen by everyone in the server. On vanilla servers, administrators' names will show as green highlighted text in the chat.
Some servers use mods to send automated messages in the chat, such as server rules or use plugins to make announcements like death notes, notifications of people joining the server, and even when cargo drops arrive.
Change between global chat or team chat by using: tab. Anything you type in team chat cannot be seen by anyone on the server. Server administrators can view your team chat.