Universität Bremen TZI "Limited Domains" are parts of an internet that may have notable differences or are just convenient to separate from the general Internet and can be delimited from that and from other Limited Domains by a defined boundary (the "border"). This memo focuses on the case where the nodes inside the Limited Domain want to interact with nodes on (or reachable via) the general Internet, but need some assistance at the border that is cognizant about the specific properties of the nodes in the Limited Domain. Self-Descriptions can provide the information needed for this assistance.