# maxRank: maximum rank [Rank] (default: 8)
# maxFile: maximum file [File] (default: 8)
# chess960: allow chess960 castling [bool] (default: false)
-# twoBoards: the game is influenced by a second board (e.g., bughouse) [bool] (default: false)
+# twoBoards: pocket pieces are added from an external source, usually from a second board (e.g., bughouse) [bool] (default: false)
# startFen: FEN of starting position (default: rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1)
# mobilityRegion: the mobility area can be defined via options specific to color and piece,
# .e.g., mobilityRegionWhiteRook, mobilityRegionBlackJanggiElephant, etc. [Bitboard]