Tracing California Car History

[68SSCamaro]

I mailed in this form last year for my car. I've owned it since 1990. The printout they sent back mostly lists the registrations from about 1999. There were some interesting fields that I couldn't figure out. I finally sent them another letter a few weeks ago asking about them. One interesting field is PREV LIC. My car has the blue plates and I figured they were from the late 70's. The date on this is in 1979 so it's the date the new plates were registered. There are 6 letters after PREV LIC. They don't make sense so I hope the DMV will tell me what they mean. That's all I got. Still no info on the car for the first 20 years.