I believe that similar idea has been posted deep in the archive.
Let Leaders and Officers be allowed to put a team announcement
- The banner last for 24h since announced OR dismissed by the player.
- The banner is Limited to one or two lines. Or if it can contain more than 2 lines, only the first 2 lines are shown in the banner, and the banner can be clicked to show the whole announcement.
- Only the latest banner is shown at the top.
- Let it has one X button to dismiss the banner.
- (optional) Send a notification to the officers if the banner is dismissed before it expires.