camber adjustment cam ?

mabey this is a dumb question, but i need to know what the camber adjustment cam is. I'm replaceing the lower ball joints, and the chilton manual says that i need to match mark the position of the camber adjustment cam before I remove the lower control arm.

If you look where the control arm bolt head is you will see what looks like an of center washer in a U shaped channel. You rotate this washer (cam) to set your camber. In your case just note the position the index marks or make a small scratch or mark on it for your reinstall.