I guess it would be the same as an international departure from Broome from the GA section, except customs are not there on the otherside of the airfield. You give them a call the day before to tell them departure/arrival times and at what airport. They come around with a big briefcase, check all of your outgoing paperwork, carnet's etc are in order, look through your passport. I have no stamps from going outbound. Once it is all clear you say thank's and cya later.