Which address is a unique local address?

The unique local address is defined as fc00::/7. Unique local addresses have replaced site-local addresses as of 2004 and are nonroutable. The valid IPv6 range is fc00:: to fd00:: despite IANA reserving fc00::/7 as the fc00:: range. The range should not be used since the 8th bit is considered the 'local bit' and is required to be a 1, as in, for example, 1111 1101 = fd. An address with a network prefix of fe80::/10 is a link-local address. An address with a network prefix of 2000::/3 is a unique local unicast address. An address with a network prefix of ff00::/8 is a multicast address.