B.5. Well-Known Multicast Group Addresses (Chapter 3, RFC 2375)
RFC 2375 defines the initial assignment of IPv6 multicast addresses that are permanently assigned. Some assignments are made for fixed scopes; other assignments are valid in different scopes. Table B-5 lists them.
Table B-6 lists the currently assigned multicast group addresses with variable scope. The addresses are noted beginning with FF0X, X being the placeholder for a variable scope value. Find an updated list at http://www.iana.org/assignments/ipv6-multicast-addresses.