In the Magpie app, a Message Board's creator or a team admin can now choose Archive board in the board's action menu, and on an archived board Restore board or Delete board. Delete board first says how many posts and comments will be deleted with the board and that its address will stop working.
An archived board says when it was archived and has no Post button, and its posts have no voting or Comment button. Once a team has an archived board, choose Show, then Archived boards, on Message Boards to find it.