A Message Board's creator or a team admin can now choose Archive board in the More menu beside the board's name. An archived board keeps its posts, comments and address, and anyone who could read it still can, but nobody can post, comment or vote. It leaves the list on Message Boards, Search and the assistant, and is listed under Archived on Message Boards. Restore board in the same menu brings it back.
An archived board can be deleted with Delete board, which first says how many posts and comments will be deleted with it. Its address stops working and cannot be used by another board.