NACK;
raw print:
array(3) { ["result"]=> string(4) "NACK" ["message"]=> string(113) "Halted; Page not found; add a 404 business rule, or move it up in the hierarchy display to customize this message" ["stacktrace"]=> array(1) { ["tip"]=> string(53) "stacktrace suppressed; only available for admin users" } } pretty print:

(raw printed)