Yes MNone is no transparency, this is usually the default, but for example if there is something transparent in the EGG file Panda will usually apply a transparency mode automatically.
Also correct, MBinary is on-off, also known as “Alpha Test” or “Cutout”.
The others are explained here (5th post): [url][SOLVED] render artifacts with transparent faces?]
MNotUsed probably means that particular mode is actually “not used”, likely there was another transparency mode before that was removed.