What determines if R source block output is wrapped in begin_example or not?

[John Hendy <jw.hendy@gmail.com>]

Greetings,

I was perplexed when a table in my exported latex/pdf document came
out garbled, to find out it's being included like "normal text." In
another block with well-behaving output, I observed the same src
header args, but it was wrapped in #+begin/end_example for free,
without me trying.

Here's a reproducible example. This output would not look right when exported:

#+begin_src R :exports results :results output :eval yes
data.frame(
  x = c(1:3))
#+end_src

#+RESULTS:
:   x
: 1 1
: 2 2
: 3 3

From trial and error, it seems the magical length is 9 where it gets wrapped:

#+begin_src R :exports results :results output :eval yes
data.frame(
  x = c(1:9))
#+end_src

#+RESULTS:
#+begin_example
  x
1 1
2 2
3 3
4 4
5 5
6 6
7 7
8 8
9 9
#+end_example

I see nothing like this mentioned in the docs on the results of evaluation:
https://orgmode.org/manual/Results-of-Evaluation.html

For now, my workaround is to use :results output code. I guess my
typical output must usually be longer than 9, or I use :results value
and manually add header rows to the generated org table, as I don't
recall dealing with this before!

Thanks for help understanding.

Best regards,
John