Automatic Spam Deletion System (ASDS) is a bad system.
Because, once you have decided NG words,
it is not necessary to allow them to be written in.
Rock54 is better than ASDS in two points.
One is that Rock54 never makes a void in the discussion,
which can be made when someone replies to the NG post before deletion.
Another is that Rock54 does not need to search around all threads later.