5396 - Textual Representation of Autonomous System (AS) Numbers
1771 - A Border Gateway Protocol 4 (BGP-4)
1930 - Guidelines for creation, selection, and registration of an Autonomous System (AS)
4893 - BGP Support for Four-octet AS Number Space
6793 - BGP Support for Four-Octet Autonomous System (AS) Number Space
6996 - Autonomous System (AS) Reservation for Private Use
RFCs related to peering