ok - before I make a request for modification. This is what I am thinking for this modification to be created.
This would allow for "groups" that can either be "tagged" or PM'd (similar to the way the DBtech's advanced used tagging works for users). In my initial thought, this would probably require a new table for the name of group, user ID's added to the group at minimum. Then a page to either register or unregister a "subscription" to that group and potential a modification to the user table to add a data point to ID if it's a "user" or a "group" user.
Since this group, ultimately would be in the user table, it could use the existing code base for the Advanced User Tagging does today.
What flaws do you see in doing this (besides probably everything

)