https://www.aec.gov.au/about_aec/research/files/informal-voting-2016.pdf#page9

Secret ballot isn’t just a right, it’s an obligation. You can’t do anything to de-anonymise your ballot. We just happen to live in a country where making sure every voter gets to exercise the franchise comes above all else, unlike the US. I definitely exaggerated a bit for the joke, but to say that getting cum on your ballot wouldn’t ever get your vote declared informal also isn’t true. Ultimately, it comes down to the Divisional Returning Officer’s discretion.

Now can we please put this to rest, I think it’s a bit much for a cum joke, don’t you?