DISC is the new DVDx too I believewilsoff said:I think I've seen it show up as DISC (44495343) somewhere in AnyTitle Deleter. I've never tried to delete it though. You'd probably need a modded version of ATD without brick protection to prevent you.
I could be wrong, and thinking of marcan's new DVDX channel which is now DISK (4449534B) since SM4.2 came out.
But its definitely not the disc channel (since thats not a title)