Special CGT rules apply to assets you own when you become a resident of Australia. You are taken to have acquired these assets at the time you became a resident.
This rule only applies to assets that you acquired on or after 20 September 1985 that did not have a necessary connection with Australia-for example, land in a foreign country. The general cost base rules apply to an asset that had a necessary connection with Australia (for example, land in Australia) when you became a resident.