Guides your super fund trustee on who to distribute your super to if you die. Non binding means the trustee is likely, although is not bound, to follow your instructions. If there is a compelling reason (say bankrupt beneficiary) the trustee can distribute your super in a different way. Rest assure they cannot give it to anyone on the street. However if you require certainty you can make a binding nomination and ensure that your super goes where you want it to.