682.This section requires a “notice of discontinuance” to be issued when the Authority decides not to proceed with  action proposed in a warning notice (section 387) or in relation to which a decision notice (section 388) was given.
683.However a notice of discontinuance does not have to be given if the effect is purely to grant an application made by the person in question.  In such cases the Act generally contains express provision requiring written notice to be given of the grant of the application.
Commentary on Sections Part Xxvi: Notices Section 389: Notices of discontinuance