I have reviewed this document as part of the security directorate's
ongoing effort to review all IETF documents being processed by the
IESG. These comments were written primarily for the benefit of the
security area directors. Document editors and WG chairs should treat
these comments just like any other last call comments.

The summary of the review is: ready

The document is well written, and short and to the point -- thanks for the good work!

A couple of minor points:

- it would be good to expand RTP on first use (even if it's common)
- For the updated sentence in section 3, saying "by requesting that IANA register that media name" -- it would be helpful to explicitly list the table name for the registry.

That's it!  Probably my shortest secdir review write up ever.