No, I didn't mean channels 5 and 6 of a 5.1 disk. I meant channels 5 and 6 (named as such) in a FLAC file, although it might be same....
Yes, it is the same for the 5.1 FLAC file. I meant to say flac; as you can use a 5.1 flac file to burn a 5.1 disc.