(1) A decision under section 50 or 51 is a reviewable Commissioner decision .
(2) A decision under this Act that is not:
(a) a reviewable Commissioner decision; or
(b) referred to in section 202F of the Income Tax Assessment Act 1936 ; or
(c) a decision under section 88;
is a reviewable Secretary decision .
(3) A decision that is a reviewable Commissioner decision or a reviewable Secretary decision is a reviewable decision .