RFC 8425: IANA Considerations for IPv6 Neighbor Discovery Prefix Information Option Flags

The Prefix Information Option (PIO) in the IPv6 Neighbor Discovery Router Advertisement message defines an 8-bit flag field; this field has two flags defined, and the remaining 6 bits are reserved (Reserved1). RFC 6275 defines a flag from this field without creating an IANA registry or updating RFC 4861. The purpose of this document is to create an IANA registry for the PIO flags. This document updates RFC 4861.