Re-open Nominations (R.O.N.)
R.O.N. stands for Re-Open Nominations. You can put R.O.N. as a preference if you feel that the remaining candidates are not suitable for the position.
When R.O.N. is listed on a ballot, there is the possibility of R.O.N. receiving a majority or plurality of the vote, and so "winning" the election. In a multi-seat election, it is possible for R.O.N. to win more than one seat.