Originally Posted by
deeruck
Might have meant clear security. You certainly have to do that, though its generally pretty painless, and will be done at the transfer point in the international terminal.
Probably also worth noting that security at this point is done to Australian Domestic standards, so liquids are allowed as carry-on. Useful if the OP wants to buy some duty free alcohol (or large bottles of perfume) on the way in to Sydney.