It a "clear" button... it replaces the IDPS with an "empty" value.
It was an early feature used to quickly hide the IDPS, for people that needed to publish a capture of the /setup.ps3 screen or record a video tutorial.
Later a "View/Hide" button was added, making the "clear" button almost meaningless.
But only clear the 2nd block not 1st?
And it not change idps just hide temporary?
It clears the 2nd half because that part has the factory code, no Ps Flag, serial number & random stamp
If you save the settings, the idps value is applied to memory.
As I commented earlier, that button now is almost meaningless. Just ignore it!