One can look for tiny, clearly defined text in multiple locations on the banknote. This includes an excerpt from Melba’s autobiography Melodies and Memories.
To make a note of some of the notable features, tilt the banknote to see a rolling color effect of the owl, which is visible on both sides of the banknote and there are multiple security features in the clear top-to-bottom window.
The fluorescent ink was used for an owl with a wattle branch, the year of print and serial number of the note, which can be viewed in fluoresce under the UV light.
The Reserve Bank of Australia has made it clear that the existing 100$ notes will remain as the legal tender and there can be no qualms about their future usage.