Boardgamegeek https://boardgamegeek.com/boardgameexpansion/190225/castles-burgundy-6th-expansion-cloisters
English - Each round, place one cloister (in place of a black-backed tile) onto the central black depot. All other rules regarding the black depot remain the same. As with other black-backed tiles, a cloister can be bought from the central black depot for 2 Silverlings, and is then placed onto an empty storage space in the bottom left-hand corner of the player’s board.