The geometries have been simplified with a tolerance of 500 m to reduce the level of detail.
Source
National Recovery and Resilience Agency, "PHN Boundaries used by the NBRA", https://data.gov.au/data/dataset/phn-boundaries-used-by-the-nbra, accessed 25 May 2023.
The original dataset is published under the Creative Commons Attribution 2.5 Australia licence, © Commonwealth of Australia 2021.