This article describes the use of CD-RW discs with Apple CD-ROM drives.

The only drives that are qualified to read CD-RW formatted discs are the 24x drives that are in desktop Power Macintosh computers (including iMac).

PowerBook CD-ROM Drives and older desktop CD-ROM drives may read some of the discs but it would be unsupported and unreliable. CD-RW is really designed as a backup format for a computer with a CD-RW drive. If you want to use CDs made on other Macintosh computers the CDs should be formatted as CD-R instead of CD-RW.