SUNroof ( that kooky name MOONroof is so 80's)
A unique option was added to the Nova line midway through the 1972 production year - a sliding fabric sunroof known as the Skyroof. Officially called the Ventura II Folding Sunroof, it was installed on 6,822 Novas in 1972. Each color carried it's own RPO code: White (RPO-WV1), Black (RPO-WV2), Blue (RPO-WV4), Pewter (RPO-WV5), Covert (RPO-WV7), Tan (RPO-WV9) and Green (RPO-YH8)
In 1973 the Skyroof option was still available but this was the last year. 3,259 Skyroof Novas were built for the 1973 model year built unlike the previous year, all colors carried the same RPO code (RPO-CF1).
http://novaresource.org/history.htm