I'm not sure this is the right forum.
The memberlist have a colmn without anything, all time. This is position. Should there written the title? Or what means position?
Basically, it's "primary membergroup"
You can set up permissions any number of ways, but when I originally set them up, I found it better (imho) to add membergroups as *secondary* groups - Devotee adn the like... But some boards set them up as *primaries*, and you'd see them listed there :)