Add text from RFC4052 Section 4

fixes #7

draft-kuehlewind-iab-rfc4053bis.md

@@ -537,6 +537,51 @@ This document describes the procedure for generating and handling
    The process of generating and approving transmission of liaison
    statements is a matter of IETF process and is specified in [RFC4052].
 
+# Approval and Transmission of Liaison Statements
+
+It is important that appropriate leadership review be made of
+proposed IETF liaison statements and that those writing such
+statements, who claim to be speaking on behalf of IETF, are truly
+representing IETF views.
+
+All outgoing liaison statements will be copied to IETF Secretariat
+using procedures defined in [6] or its successors.
+
+For a liaison statement generated on behalf of an IETF WG, the WG
+chair(s) must create a statement based on appropriate discussions
+within the WG to ensure working group consensus for the position(s)
+presented.  The chair(s) must have generated or must agree with the
+sending of the liaison statement, and must advise the AD(s) that the
+liaison statement has been sent by copying the appropriate ADs on the
+message.
+
+For a liaison statement generated on behalf of an IETF Area, the
+AD(s) must have generated or must agree with the sending of the
+liaison statement.  If the liaison statement is not sent by the ADs,
+then their agreement must be obtained in advance and confirmed by
+copying the ADs on the message.
+
+For a liaison statement generated on behalf of the IETF as a whole,
+the IETF Chair must have generated or must agree with the sending of
+the liaison statement.  If the liaison statement is not sent by the
+IETF Chair, then his or her agreement must be obtained in advance and
+confirmed by copying the IETF Chair on the message.
+
+For a liaison statement generated by the IAB, the IAB Chair must have
+generated or must agree with the sending of the liaison statement.
+If the liaison statement is not sent by the IAB Chair, then his or
+her agreement must be obtained in advance and confirmed by copying
+the IAB Chair on the message.
+
+In cases where prior agreement was not obtained as outlined above,
+and the designated authority (AD, IETF Chair, or IAB Chair) in fact
+does not agree with the message, the designated authority will work
+with the liaison manager to follow up as appropriate, including
+emitting a revised liaison statement if necessary.  Clearly, this is
+a situation best avoided by assuring appropriate agreement in advance
+of sending the liaison message.
+
+
 # Security Considerations
 
    One of the key considerations in developing this process has been the