'Having a good sense of humour' is something most societies and cultures pride themselves upon. But in Australia, joking of all kinds can be targeted at all social levels and while witty is good, crude will also pass. For Australians, using (or at least tolerating) humour is not so much permitted, as compulsory. Our national identity is almost synonymous with the right to take the mickey (aka - take the piss - a cruder, older form of the expression, now acceptable again). Our culture deploys humour as a weapon to identify those who are truly 'at home', in the land and the society. Thus it's not so much the nature of the humour we use as how we use it that indicates our 'Australian-ness'.