A cheque-to-self is a way to move funds between accounts held in your name. Before 1 October 2019, Citi was the only issuer in Australia that offered a cheque-to-self option on its balance transfer credit cards. With this option, instead of transferring a balance from one account to another, you would request a cheque that you could use to pay off anything.
But since 1 October 2019, there has been no way to get a cheque-to-self balance transfer in Australia.