rtp RFC documents are non-free?
Summary
RFC documents are non-free, because they don't allow modification. Please see https://wiki.debian.org/NonFreeIETFDocuments.
In particular:
However, this document itself may not be modified in any way, such as by removing the copyright notice or references to the Internet Society or other Internet organizations, except as needed for the purpose of developing Internet standards
Sounds non-free to me.
Perhaps the documents could be removed from the final tarballs, as the autotools dist used to do?