The IAB has published RFC 8153: Digital Preservation Considerations.

Abstract: The RFC Editor is both the publisher and the archivist for the RFC Series.  This document applies specifically to the archivist role of the RFC Editor.  It provides guidance on when and how to preserve RFCs and describes the tools required to view or re-create RFCs as necessary.  This document also highlights gaps in the current process and suggests compromises to balance cost with best practice.