Gerard,
Just by signing up for this web forum, you become a "Basic Member". As a basic member of the Group, you can contribute to the forum, participate in local/international events, and more (see the benefits listed elsewhere on this web site).
If you pay the dues to become a "Full Member", then you get Pagoda World, a window sticker, an ID card, access to additional web pages on our web site, ability to vote when the Group has new business (electing officers, changing the Charter, etc.), and more.
It sounds like your son just needs his own ID on the web forum, so he would have his own Basic Membership.
Rodd
1966 230SL Euro
1994 E420