[Perenti]

And those that don't vote have to show a very good reason, or pay a fine, or face gaol.

[grues-dinner]

Correction: those that don't enter a polling station. What you do in there is up to you. You can cast a vote, spoil the ballot, cast a "donkey vote" (numbering the options in the order printed), leave the ballot empty, as long as it goes in the box.