Normal operational Reminders will appear at the top of the associated page like this!
Reminders that represent an Alert of some type will look like this
Reminders of a critical nature will appear similar to this!
Usually, Reminders expire based on calendar date and/or time, or by the User no longer being associated with the Reminder (e.g. the Referee was removed from an upcoming Assignment).
You can also use Reminders in other Segments of the Site, if desired. For example, Administrators can be notified that a new User has requested Site Registration.