No default labels, is it intentional?

[Göran Uddeborg]

I'm running a "restorecon -n -R -v /" from cron once a month, just to
be careful and know what is happening.  Last night when it ran, I got
a lot of error messages like these:

restorecon:  Warning no default label for /dev/pts/3

and

restorecon:  Warning no default label for /tmp/efs0YYVa79.html

There were a couple for things in /dev, and lots of them for things in
/tmp.

I have lately been upgrading bit by bit to Fedora 18 (the beta,
strictly speaking, since the final release isn't officially out at the
time of this writing), so I assume the new message is related to these
upgrades.  But why?  When I list file contexts, I see rules like this:

/dev/pts(/.*)?                                     all files         
<<None>>

So I guess it is not a simple mistake.  But what is the reason?  Why
don't some /dev entries, and almost the entire /tmp directory, have
any default context any more?