Yes, they can. Do any of these codes sound familiar to Chevy fans? M20, M40, N41, N10? These codes are all part of the Firebird options and are common with Camaro.
One notable conflict in RPOs is JL2, which is power front disc on a '69 Firebird (per Car Distribution Bulletin 3/27/69) but air induction hood on a Camaro.
But I believe a few late cars with spoiler option exist.
