Ann: Square, Inc. announces plans to acquire Afterpay, page-81

It means Square will have an ASX listing via Chess Depository Interests, so that when Square acquires your Afterpay shares, you will get these new things SQ.ASX or whatever they are going to call it, and you can trade them here. It makes life easier for Aussie shareholders of US-listed companies so you don't have to go to the trouble of trading in the US (not that difficult, but still more complicated than just trading Aussie).