Hi all; Just a procedural question. Though rfc2026 says: A specification for which significant implementation and successful operational experience has been obtained may be elevated to the Internet Standard level. An Internet Standard (which may simply be referred to as a Standard) is characterized by a high degree of technical maturity and by a generally held belief that the specified protocol or service provides significant benefit to the Internet community. does rfc1981bis qualify? It seems to me that rfc1981 operationally failed and rfc4821 was developed, which means PMTUD can be IS only when rfc4821 become IS. Or, do I misunderstand something? Masataka Ohta