When this command is called in compressed mode, that is, with recurring =1, the query interface goes through the Delete Log database and returns all the non-repeating entries and the master components deleted that match the criteria. This pass ignores the recurring instances that are stored in the database. This does not return any master entries associated with the deleted recurring instances that are still active. Those active master entries are returned using the fetchcomponents_by_lastmod command. If all the instances in a recurring chain are deleted, the master component returns dtstart, dtend, rrules, rdates, exrules, exdates and uid.
When the command is called in expanded mode, that is, with recurring=0, the query interface goes through the Delete Log database and returns all instances of recurring components. Specifically, it does not return the master component.