UTIL FLASH

Usage: UTIL FLASH [LOCAL|NETWORK] <message>

This will send either a local newsflash or a network-wide newsflash. This command mimics the server commands /lflash or /nflash.

Example:
/as util flash local -=This is a local newsflash=-

If you had a regular event on your server, you could script a newsflash to inform people as part of that event.