Terminology

@AC Actually I'm quoting from the seminal paper: Peter M. Chen , Edward K. Lee , Garth A. Gibson , Randy H. Katz , David A. Patterson, RAID: high-performance, reliable secondary storage, ACM Computing Surveys (CSUR), v.26 n.2, p.145-185, June 1994. Section 3.2.7.

The point is that Chen defined the terms. Since then the terms have been abused, and also extended. But since this is generally the paper which is accepted as the basis for most RAID discussion I think I remain correct. No, I don't quote Wikipedia.

There is some wiggle room, the paper only discusses two bit errors corrected with P+Q, but is should be clear that the fundamental mechanism scales withing the same architecture. Thus RAID 6 remains the correct term for extended parity beyond 2, unless the system is a RAID 2 style.