Replacing my Rotors this weekend:

From what it looks like the rear rotors are held on just by the rim, held in place by caliper. The front ones had two phillips head screws holding them on the rear ones didn't. I just want to make sure I am not missing something on the back rotors. Anyone else have experience with this?

Most cars are like this. There really is no reason to have a diffrent type of fastener system to hold the rotor on and then bolt the rim. This In turn sandwhichs the rotor between the rim and hub.
Couldn't figure why the screws are there. Anyone?