I am glad to see a simpler presentation of the castling rules for Chess960.
The length of the initial rules presentation I had seen was rather
offputting, and what John has proposed is, in my opinion, a step in the
right direction.
My question involves other requirements for castling. In ordinary chess,
there is the requirement (3.8.ii.2.b) that the squares between the king
and the rook in question must be empty. This rule ensures, among other
things, that both the king and the rook have open destination squares. I
don't see such a requirement explicitly in John's post, and I suggest
that this be added or, if the rule is not necessary, that an explanation
of castling in a situation like BRKNNQ.. (with the spot the king would
occupy after castling already being occupied by another piece) be
provided.
Pete