I thought only what appears on screen is
Star Trek canon.
It's even narrower than that, according to my understanding. If it's on screen, was shown on television/released to theaters, and is
meant to be seen at normal resolution (as opposed to obsessive fanboy scrutinization/maximum magnification), it's canon. In other words, Director's Cuts on DVD, deleted scenes, in jokes/small print,
etc. are most emphatically
not canon. For example, we have no idea who
Enterprise-E's new X-O is, because that scene was cut from Star Trek:
Nemesis.
On the other hand, stuff like the
Saladin-,
Hermes-,
Ptolemy- and
Federation-class starships, seen only in diagram but meant to be visible and recognizable to those having read the
Star Trek: Star Fleet Technical Manual by Franz Joseph,
are (at least arguably) part of the canon. [Those specific names, though, really aren't, since they were never meant to be visible. I just use them for convenience's sake here.]
The Relaunch is
by no means canon—not even
close. It's instead a variant reality many
Trek fans enjoy, or alternately part of a particular individual's personal continuity—as is Diane Duane's Rihannsu universe and every standalone novel for
Trek ever written.
So a scene depicted on my old
Star Trek lunchbox and one in the Relaunch novel
Unity have precisely the same level of canonicity—that is to say, none at all. I'd bet the latter, though, makes it into a few more personal continuities.
Interestingly enough, though, the statement on canon at StarTrek.com has been softened somewhat of late. So I guess there's hope for my ol' lunchbox after all.