Wow. Didn't realize that the algorithm was that advanced on Audio CDs. Regardless, data CDs definitely have *more*.

Here's some relevant info I found:

Data Modulation & Error Correction, which describes the EC on all CDs.

CD-ROM Sectors, which describes the layout of CD-ROM sectors, including where the EC is, but doesn't describe the EC itself. Can't seem to find that anywhere.

Edit: this page claims that it's just another round of CIRC.