http://www.rfc-editor.org/rfc/rfc7300.txt
RFC 7300: Reservation of Last Autonomous System (AS) Numbers, J. Haas, J. Mitchell2014-07-01T23:00:00-00:00This document reserves two Autonomous System Numbers (ASNs) at the end of the 16-bit and 32-bit ranges, described in this document as "Last ASNs", and provides guidance to implementers and operators on their use. This document updates Section 10 of RFC 1930.