#+Property: :results silent

#+name: data
| 1 | 2 |
| 2 |   |
| 3 | 4 |
| 4 | 5 |

#+begin_src gnuplot :var data=data
  set key outside
  set xrange [-1:4]
  set yrange [0:6]
  plot data u 0:1, '' u 0:2
#+end_src

#+begin_src gnuplot :var data=data :missing "?"
  set key outside
  set xrange [-1:4]
  set yrange [0:6]
  plot data u 0:1, '' u 0:2
#+end_src