I am building a simple membership system where users can feel they "belong to" themed groups. I did look at some of the Clan systems that gaming forums use but I quickly got lost as I'm not a gamer. But possible there's already something like this. Attached mockup - most of this is in place. But I would apprecfiate advice on a crucial issue. What I have so far is each Category on the node tree is colour coded on the category bar - matching the title, forum titles, thread titles, other sub-header bars. A navigation menu in the sidebar also matches the colours. So the colour categories tell you where you are and help identity. Clicking the Category title opens the standard dedicated category page. Only these pages are all colouir coded per categopry, with a logo graphic per category. I am now coding (with help ) the forums to also match the colour and logo design of their category. On the Category page under the forums is space for a Library/ Resources/ Links section (editable in an include template). Here I put either key internal links or external sites of key interest to this category. Members are invited to propose links to add on a thread for this purpose. So far so good. Here's the decision point. MEMBERS of this Category - or of any of its subforums - rests on having a user setting to receive notifications. I have an add-on already where I can allocate notification to a Category or a forum and there will be a default one. In a couple of days it will be done for users to opt in to notification on a forum basis. Where they are "notified" they will appear on the Members list of that Category or forum. The list gives avatar, username, location, a Start Conversation link, user postings and other memberships. I'm wondering whether to make it that "membership" of a Category rests on "membership" of a single forum, or on 2 or 3? It's not a large busy forum though it has its moments Finally can anyone see if I've overlooked anything important?