@PJK ! Multisite System allows to create customized communities on a single XenForo database. From your description, it seems Multisite System will not help in your case. If you'll build a competitions website based on XenForo (with its nodes, style, etc.) and will want to have 2 domains, one for XenForo forum and one for competition site based on the same XenForo database, Multisite System will work for you.