190.This section makes it an offence to issue an advertisement or other information of a kind specified in listing rules (for example an invitation to purchase securities) unless the contents have been approved by the competent authority or the issue of an unapproved advertisement or information has been authorised by the competent authority.  This offence only applies where listing particulars are, or are to be, published.
191.Subsection (3) provides a defence against this criminal offence where someone reasonably believed that the advertisement had been approved or its issue authorised by the competent authority.
Commentary on Sections Part Vi: Official Listing Section 98: Advertisements etc in connection with listing applications