Is there a clear summary somewhere of why multiple concurrent queries do
not satisfy this requirement?
A slightly irrelevant pedantic correction:
> The distinguishing idea was to build in some kind of integrity of
> RRsets using feedback signaling that allows to indicate empty RRsets
> ("nodata" indication per RRtype); caches that do not "know" the
> entire RRset of an RRtype asked for do not send a partial RRset
> but indicate that the response does not answer for such RRtype.