After reading a banner message, a user can dismiss it, which will hide the banner until it is next updated. Since this is also possible for banner message editors, messages tend to remain on the site for an indefinite amount of time because banner message editors forget to remove them ("Out of sight, out of mind").

We should therefore allow banner message editors to only temporarily dismiss the banner: After a certain amount of time, the banner will reappear for them, and they can decide to remove it from the site or to dismiss it temporarily again, if the message is still relevant.