All of the changes listed in Appendix 2, plus the following.
To detect and recover from BGP connection collision, a new field (BGP Identifier) has been added to the OPEN message. New text (Section 6.8) has been added to specify the procedure for detecting and recovering from collision.
The new document no longer restricts the border router that is passed in the NEXT_HOP path attribute to be part of the same Autonomous System as the BGP Speaker.
New document optimizes and simplifies the exchange of the information about previously reachable routes.