Procedures for protocol extensions
This document discusses issues related to the extensibility of IETF protocols, including when it is reasonable to extend IETF protocols with little or no review, and when extensions need to be reviewed by the larger IETF community. Experience with IETF protocols has shown that extensibility of protocols without IETF review can cause problems. The document also recommends that major extensions to IETF protocols only take place through normal IETF processes or in coordination with the IETF.