For me the most important point is that it is managed on IETF (or IETF's
contractor) servers.
as no private data are involved, i am curious why?
Because public does not mean unlimited availability. Let's say that
the IETF decides to use a collaboration tool hosted by a service run
by an external company. The data is public (although it can be stored
in a proprietary format) so anybody can consult it. But suddenly the
service is bankrupted/become collateral damage when servers are
seized/has its certificates expiring/etc... Unless someone did some
preventive data liberation, the data is no longer available, at least
until whatever caused the problem is solved.
so your criteria acctually open and continual availability, and
availability of export. i think these would apply well to ietf or
whatever services as well.
randy