From the implementation checklist: :ref:`OpacSuppression <opacsuppression-preferences-label>`␠: Decide if you want to hide items marked as suppressed from the OPAC search results OpacSuppression is about hiding records, not items.
... Just realized this was already fixed in the 20.11 manual: https://koha-community.org/manual/20.11/en/html/implementation_checklist.html
Found another occurence: https://koha-community.org/manual/20.11/en/html/catalogingpreferences.html?highlight=opacsuppression OpacSuppression Default: Don’t hide Asks: ___ items marked as suppressed from OPAC search results. Restrict the suppression to IP addressesoutside of the IP range ___ (Leave blank if not used. Define a range like 192.168..) Redirect the opac detail page for suppressed records to ___ Display the following message on the redirect page for suppressed biblios ___. The description of the system preference in Koha has since be updated so the manual should be changed to match it.
Are you still working on this one Victoria?
I corrected the system preference descriptions for 21.05