Procedures for Protocol Extensions and Variations
RFC 4775 also known as BCP 125

Received changes through RFC Editor sync (changed abstract to 'This document discusses procedural 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 or variations need to be reviewed by the IETF community. Experience has shown that extension of protocols without early IETF review can carry risk. The document also recommends that major extensions to or variations of IETF protocols only take place through normal IETF processes or in coordination with the IETF.

This document is directed principally at other Standards Development Organizations (SDOs) and vendors considering requirements for extensions to IETF protocols. It does not modify formal IETF processes. This document specifies an Internet Best Current Practices for the Internet Community, and requests discussion and suggestions for improvements.')