What format is used on CD RW disks?

This early introduction along with the lack of standards for software, file systems and disks, low recording speeds, physical incompatibility, along with the cost of the recording devices and the disks themselves back in the early 1990s, as well as the introduction of the relatively more economical CD-R disks and (especially) faster and more compact drives restricted the CD-MO to niche markets, and the format was almost forgotten, being essentially replaced by phase change CD-RW and other, better specified magneto-optical media. As of 2006, it is very hard to find actual CD-MO record-capable drives or even CD-MO disks.