[O] Manual does not list :results output graphics as babel header arg

[John Hendy]

I have typically outputted graphics from R via tikzDevice manually,
but gave my first whirl to just including things via the :file
argument in my block header. In the process, I was trying to get this
to work and found I needed to use:

-----
:results output graphics
-----

This is listed on Worg ob-R-doc:
- http://orgmode.org/worg/org-contrib/babel/languages/ob-doc-R.html#sec-4-3

But I didn't originally know about it, as it's not a listed header
argument in the manual, which is where I check since they're all
listed in one place:
- http://orgmode.org/manual/results.html#results

Does the manual only list universal babel header arguments and R is in
a subset of ones using =:results output graphics= or should it be
there?



John