In my opinion, until there is a conforming C11 compiler available on some
platform, discussion of C11 is purely theoretical and belongs in
comp.std.c.
comp.std.c if for discussions about the C standard: what it says now,
what it said in previous versions, what it should say in future
versions, whether a given piece of code had defined behavior according
to that standard, whether a given compiler conforms to that standard,
etc. Discussions about the language defined by that standard are
off-topic in that group, except insofar as they also involve issues
about the standard itself. It seems like a subtle distinction, but it
really isn't; "Are compound literals allowed by the standard?", "Is it
feasible to implement compound literals?", and "Should compound literals
be removed from the standard?" are all on-topic. "How do I use compound
literals?" is off-topic there.
comp.lang.c.moderated is for discussions of the standard C language,
even purely theoretical aspects of it, such as how to use features of
C11 that no one has implemented yet. comp.lang.c is a group with no
particular charter, that is commonly used for that same purpose, but is
also heavily troll-infested. It's also, for some reason, used instead of
comp.compilers.lcc for announcements concerning lcc-win32. If and when
more people to move their discussions over to comp.lang.c.moderated
(don't hold your breath), we can finally abandon this newsgroup to the
trolls and the advertisers.