(1) Section 23 of this Act shall not apply to a class of advertisement specified from time to time by a supervisory authority for the purpose of exempting from that section -

(a) advertisements appearing to a supervisory authority to have a private character, whether by reason of a connection between the person issuing them and those to whom they are issued or otherwise, or

(b) advertisements appearing to a supervisory authority to deal with investments only incidentally, or

(c) advertisements issued to persons appearing to a supervisory authority to be sufficiently expert to understand any risks involved.

(2) An exemption under subsection (1) of this section shall be subject to such conditions as may be specified by a supervisory authority when granting the exemption.