Whats the difference between a valet key and regular key on a 1992 Honda Prelude?

Normally the difference between a Valet and Master key is the Valet key will not work in the glove box or trunk of the vehicle. The actual differences in the keys are either the grooves in the key or the thickness of the key which restrict it from going into the locks. Occasionally the valet key may not have certain cuts on it to work those locks.