Code Logic help

Hi
I have a piece of code which I don't understand fully.

  recSO.COPYFILTERS("Record 1");
  SETRANGE("Order No","Order No");
  FIND('+');
  SETRANGE("Order No");
  "Record 1".COPYFILTERS(recSO);

What does it do? I mean, what happens when you clear the filter after a FIND('+') ?