This is an anonymous note, so they cannot reasonably respond and likely would not know of your comment.

This road has been tagged at 20km/h since it was added 5 years ago. After a little bit of research,I found that all residential streets in Victoria are now 30kmh, and then I confirmed this with the Victoria open data portal that shows this street as 30km/h.

It was likely incorrectly tagged upon creation, potentially from an unsanctioned sign placed by a resident. I will update this street.