23.— (1) Subject to subsection (2), any act to be performed or function to be discharged by the Revenue Commissioners which is authorised by this Act may be performed or discharged by any one or more of their officers acting under their authority.

(2) The general delegation referred to in subsection (1) shall not apply in the case of―

(a) the authorisation of Revenue officers to perform any acts or functions that require authorisation by the Revenue Commissioners, and

(b) the making of regulations under this Act by the Revenue Commissioners.