Please forgive my image it is a little outdated now...
The new/latest recommendation for every CPS3 owner is to remove that little white plastic cover.
Inside you might find a battery, and this is exactly the reason why its recommended to check.
IF that battery leaks, it will totally destroy the custom IC near it (I'm seen some horrifical shots of the chip feet completely corroded/melted off).
If you have a battery under the cover, snip it off ASAP!!!
If you don't have a battery under the cover, your fine.
Even from the factory some early boards have them, and later ones don't... Has zero effect on the operation of the PCB.