This version addresses feedback received during working group last
call. The Title, Abstract, and Introduction have been rewritten;
the Context and Rationale have been significantly updated; the
discussion of the use of OAM has been expanded; and there have
been various more minor fixes throughout. The fundamentals are
unchanged, but it is hoped that this version of the draft more
clearly positions itself and sets the context. Thanks to Joe Touch,
Dimitri Tikonov, Christian Huitema, David Black, Emile Stephan,
and the security directorate for their feedback.