Documents going to countries that are not party to the Hague Convention generally require an authentication. These countries include China, the UAE, Iraq, and many others.
Some countries impose restrictions on how an authentication is affixed. For example, you may not be allowed to have an Australian notary public certify your foreign document as a true copy for the purposes of having an authentication affixed.
It may be required to be signed by their Embassy in Australia after DFAT has stamped it and their Ministry of Foreign Affairs in the capital city. The requirements vary from country to country.