I just learned about .rev files with Winrar -- that if you have a 10-part RAR volume, for example, plus one .rev (recovery) volume -- that .rev volume will be able to "fix" any -one- corrupted volume.

How is it able to do this? Obviously there's something I'm not understanding, as I don't understand how one volume could have the "data" to fix any/all of the individual broken volumes.

I'd guess that it's because the volumes aren't broken up like I tend to imagine -- each volume having individual files of the whole packed into them, but rather, it's viewed as one continuous "file", so to speak, of data. And that there must be some type of CRC'ish repair work --

But I just don't understand how you could have 9 working volumes, with 1 damaged, but a recovery volume that would be able to repair -any- one of those volumes. How is it able to hold "all" of the data in just one recovery file?