I think the "Rs" in there are supposed to be the little Registered Trademark Rs, not an actual "R". The only new formats I'm aware of are DD+ and some new version of DTS, which are backwards compatible, and neither are "R", and neither are mentioned in the users manual.
The 90x8 is also a typo (common for early Marantz info); the user's manual lists it as 90x7 and it only has 7 channels of output.