cell phone problem

[joechou0013]

I have a couple of Cingular cell phones and when I remove the batteries out of both of them, I see a paper dot on the back of the phone. The dot looks like the the left over dot of paper when you hole-punch papers. What do those dots mean? On one phone, the paper dot is white and on the cell phone the paper dot is yellow. Why are they different colors? Are they used to distinguish different phone types, brands, etc? I am just curious...