What would happen if we increased the board with one more square
to the bottom right? The corner square provides a hiding nest for the king
should the player want to invoke play on the same wing and advance with
the pawns.

Extended castle rule: besides normal castling one can choose to move
the king three squares instead of two. The rook ends up on its usual
square.
The extended castle rule also makes play on the wings easier to achieve.
Queenside castle becomes more attractive. The extra corner squares will
enhance the strategical possibilities.

Read more he
http://hem.passagen.se/melki9/neoorthodoxchess.htm

M. Winther