(1)  In this section, common law defence means a rule or principle of the common law that renders any circumstances a justification or excuse for any act or omission or a defence to a charge upon indictment.

(2)  For the avoidance of doubt, the repeal effected by section 4 of the Criminal Code Amendment (Year and a Day Rule Repeal) Act 1993 is not to be taken as reviving any common law defence that might, but for this section, be revived by the repeal.