H. G. Muller wrote on Wed, Jan 25, 2012 03:56 PM UTC:
Indeed, the rules for castling could need clarification. In Fairy-Max I use the rule that _after_ castling none of the squares skipped over by the King should be under enemy attack. With only ordinary leapers and sliders this is as good as any definition (in combination with the requirement you cannot castle out of check).
I agree a more logical generalization of the rules would be to specify sub-state of castling, stepping the King towards the Rook as many times as needed, and then hopping the Rook to its target square. The requirement should then be that in none of the sub-states the King would be in check, would the castling be terminated there.
Compare this to Seirawan gating, where the King is also not allowed to be in check after the development move of the piece, but before the gated piece is dropped on the evacuated square.