yo soy el warg

Try figuring this one out!

I was looking at my SPID RPO codes on my 1C5 IROC-Z and noticed both these codes on it. They seem to be for the same thing, a Radio, Stereo, Cassette, Clock, S/S, Equalizer.

The build sheet list only says: UX1 FM S/SC EQ

The window sheet list only says: YE2 ELEC TUNED AM/FM ST RAD W/SK&SC CASSETTE TAPE, CLOCK, & ERSS

The SPID list has both YE2 and UX1 on it. Was YE2 the RPO for the package
including everything in the sound system and UX1 only for the radio?

I've found that :
YE2 was offered in 1983 on all Camaro models and in 1984-86 on all Camaro models except Berlinetta.

Then in 1987 YE2 was no longer available as an option. Then came UX1 which seems to be the same thing as YE2. But UX1 only came with the 1SC package and only on the IROC coupe and convertible as standard equipment.

Then in 1988 and 1989 UX1 was only available with the FZA3 IROC-Z coupe and the CZA3 IROC-Z convertible as packages.

Then once again in 1990, 91, and 92 UX1 was available as an option till it was phased out at the end of the 1992 production year.