If you quote your TFN then the contributions received and benefits paid by the RSA will be taxed as above.
However, if you do not quote your TFN the RSA provider must withhold tax at the highest marginal tax rate (plus Medicare levy), when you withdraw your benefits.
TFNs can be given to your RSA provider by you or your employer (if authorised by you).
The Privacy Act 1988 applies to RSAs, which means that strict penalties apply to employers or superannuation providers who misuse your TFN.