Preventing Thread Necromacy

Dearest /prog/,

I heard /prog/ has a script preventing  Thread Necromacy (contained in the secret area of hax) i.e. when old threads are bumped from the abyss they are not visible. Now now, I know by asking /prog/ I have 2 problems; but I'd be grateful if you could share it.

                       //`'''```,
             o        // LISP   `.,
       ,....OOo.   .c;.',,,.'``.,,.`
    .'      ____.,'.//
   / _____  \___/.'
  | / ||  \\---\|
  ||  ||   \\  ||
  co  co    co co