A server MUST discard any Solicit, Confirm, Rebind, or Information-request messages it receives with a Layer 3 unicast destination address.
For example, unicast transmission is not allowed for Solicit, Confirm, and Rebind messages (see Sections 18.3.1, 18.3.3, and 18.3.5, respectively), even if the Server Unicast option (see Section 21.12) is configured. For Request, Renew, Information-request, Release, and Decline messages, it is allowed only if the Server Unicast option is configured.
These statements contradict each other. Are unicast transmissions (after the receipt of a Server Unicast option) permitted or not?