173.This section allows the competent authority to authorise the omission of information required by listing rules to be included in listing particulars in certain circumstances.  These circumstances are set out in subsection (1); namely, that the disclosure of the information would be contrary to the public interest, would be seriously detrimental to the issuer (for example the disclosure of commercial secrets), or would be unnecessary given the kind of people who could be expected to buy or sell those securities (for example, if the securities were only dealt in by professionals).
174.Subsection (2) provides that information cannot be omitted where it would be seriously detrimental to the issuer if that information is essential in order for a person to make an informed assessment.  (“Essential information” is defined in subsection (6).)
Commentary on Sections Part Vi: Official Listing Section 82: Exemptions from disclosure