AVZ chart, page-8982

Jongo,

Division 293 tax is an additional 15% tax on superannuation contributions (on top of initial 15% tax paid on super contributions (i.e. 30% in total) = $7,500 ($ 3,750 x 2) on maximum contribution of $25,000 ... which is imposed on individuals whose taxable income (adjusted by contribution) is over $250 k (was $300 k before 2017).
Mind you, if you are at that level of income the tax benefit of the $25 k contribution woukd have been at highest tax bracket = 47% = $11,750.
Additional Division 293 tax at
15% is in effect reducing this 47% tax benefit for "wealthy" taxpayers who make superannuation contributions to 17% = 47% less 15% x 2.
Tax is in effect not fair for wealthy (high income) taxpayers but meant to be fairer for lower income taxpayers, by in effect reducing the potential higher tax benefit for superannuation contributions.
No superannuation contributions = no tax saving or benefit = no additional Division 293 ... and conversely no tax saving or benefit by making superannuation contribution in the first place.
Yes, I obviously am an accountant.
GLTAH,
Zippy1