Section 5 of RFC 5617 created some namespaces [1] in the IANA registry.
These namespaces require IETF Review. There is an easy way for the IESG to
perform the registry clean-up. The easy way might end up being
problematic.
I'm not sure I understand the question or the problem. We normally
leave registries and registered entries alone. What sort of cleanup
are you looking for?
We could put a notation in the registry that says it's historic, but
anyone looking at the registry's reference document will see that
anyway.
Barry