/// between_bb() returns a bitboard representing all squares between two squares.
/// For instance, between_bb(SQ_C4, SQ_F7) returns a bitboard with the bits for
-/// square d5 and e6 set. If s1 and s2 are not on the same line, file or diagonal,
+/// square d5 and e6 set. If s1 and s2 are not on the same rank, file or diagonal,
/// 0 is returned.
inline Bitboard between_bb(Square s1, Square s2) {