These are what different recording formats on the Sound Devices 688 / 633 and 664.
The different modes are Wav poly / wav poly (ISO Only) / wav poly (LR Only) / wav poly (X1X2) / MP3 (LR) / MP3 (X1X2) / wav mono / Wav Mono (ISO only). All of these only work if you record enable the relevant tracks.
This is a collection of sound mixer/recorder I can find/remember/google so please do comment below if you want another one added. Feel free to bookmark this page for easy manual reference in the future.
I decided that I would offer a collection of videos for all the people that ask me questions about using and setting up the Sound devices 633. Unlike my Sound Devices 664 video which is in one massive chunk (will be edited down to separate ones soon) this one has nice clear sections with lots of useful tips and advices on how to setup the Sound Devices 633. Don’t forget at the very bottom of this page you can leave a comment to what you saw and any questions for a specific video you can always leave on here or Youtube.