Dont take my word for it as I am not a financial person but in...

Dont take my word for it as I am not a financial person but in previous capital returns I have recieved what happens is the company needs to get approval from the ATO that no tax needs to be paid on the capital return.
After approval I believe usually your cost basis needs to be reduced by the capital return amount. example: average entry price in MYX is 20c when you go to sell your shares your average cost basis becomes 20c-3.8c so your cost of shares becomes 16.2c so if you sell for a profit you will be paying some tax on that 3.8c CR.
Happy to be corrected?