Confirmed U198+ (S29+) members have been divided into sub-groups. The rationale for this is more fully explained on our main webpages:
The "superfamily" is a robust sub-group proposed by John Sloan in April, 2008. It appears to represent a significant "family" within "regular" (type "r") S29/U198. It has a very strong "motif" of Y-STR marker values and appears to represent a large "family" who shared a common ancestor well before the adoption of surnames.