'Super' really isn't a valid genetic term. It's a term coined by the Ball Python industry to describe a snake that has a co-dominant mutation and is Homozygous rather then Heterozygous. (Pastel -heterozygous for the pastel trait, SUPER pastel - homozygous for the pastel trait, etc...) A Double Super would just be an animal that is Homozygous for two different mutations.