Never knew that. Might explain why before I got this custom drive some RVT-R's showed as blank DVD-R's in normal DVD drives. My next task is to crack Wii U CAT-R dumping lol. Possibly getting some CAT-R Sonic beta's in the coming months. Going to see if a retail Wii U drive can be hacked to connect to a PC first, Then I'm going to try and grab the CAT-R firmware and reflash the drive or something.